St. Peter's Basilica in Vatikan (By : Kezia)

Designed principally by Donato Bramante, Michelangelo, Carlo Maderno and Gian Lorenzo Bernini, St. Peter's is the most renowned work of Renaissance architecture and remains one of the largest churches in the world. While it is neither the mother church of the Roman Catholic Church nor the cathedral of the Bishop of Rome, St. Peter's is regarded as one of the holiest Catholic sites. It has been described as "holding a unique position in the Christian world" and as "the greatest of all churches of Christendom".

In Roman Catholic tradition, the basilica is the burial site of its namesake Saint Peter, one of the twelve apostles of Jesus and, also according to tradition, the first Bishop of Rome and therefore first in the line of the papal succession. Tradition and some historical evidence hold that Saint Peter's tomb is directly below the altar of the basilica. For this reason, many Popes have been interred at St. Peter's since the Early Christian period. There has been a church on this site since the time of Constantine. Construction of the present basilica, replacing the Old St. Peter's Basilica of the 4th century, began on 18 April 1506 and was completed on 18 November 1626.

St. Peter's is famous as a place of pilgrimage, for its liturgical functions. Because of its location in the Vatican, the Pope presides at a number of services throughout the year, drawing audiences of 15,000 to over 80,000 people, either within the Vatican Basilica, or in St. Peter's Square. St. Peter's has many strong historical associations, with the Early Christian church, the papacy, the Counter-reformation and with numerous artists, most significantly Michelangelo. As a work of architecture, it is regarded as the greatest building of its age. St. Peter's is one of the four churches of Rome that hold the rank of Major Basilica. Contrary to popular misconception, it is not a cathedral as it is not the seat of a bishop; the cathedral of the Bishop of Rome is located in the Archbasilica of St. John Lateran.

Status

St. Peter's Basilica is one of four Papal Basilicas or Major Basilicas of Rome the others being the Basilica of St. John Lateran, Santa Maria Maggiore and St. Paul outside the Walls. It is the most prominent building in the Vatican City. Its dome is a dominant feature of the skyline of Rome. Probably the largest church in Christendom, it covers an area of 2.3 hectares. One of the holiest sites of Christianity in the Catholic Tradition, it is traditionally the burial site of its titular Saint Peter, who was one of the twelve apostles of Jesus and, according to Catholic Tradition, also the first Bishop of Antioch and later first Bishop of Rome, the first Pope. Although the New Testament does not mention Peter's martyrdom in Rome, Catholic tradition, based on the writings of the Fathers of the Church,[clarification needed] holds that his tomb is below the baldachin and altar; for this reason, many Popes have, from the early years of the Church, been buried there. Construction of the current basilica, over the old Constantinian basilica, began on 18 April 1506. At length on 18 November 1626, Pope Urban VIII solemnly dedicated the church.

St. Peter's Basilica is neither the Pope's official seat nor first in rank among the Major Basilicas of Rome. This honour is held by the Pope's cathedral, the Archbasilica of St. John Lateran which is the mother church of all churches and parishes in communion with the Roman Catholic Church. However, St. Peter's is most certainly the Pope's principal church, as most Papal ceremonies take place there due to its size, proximity to the Papal residence, and location within the Vatican City walls. The "Chair of Saint Peter" or cathedra, an ancient chair sometimes presumed to have been used by Saint Peter himself, but which was a gift from Charles the Bald and used by various popes, symbolises the continuing line of apostolic succession from Saint Peter to the present pope. It occupies an elevated position in the apse, supported symbolically by the Doctors of the Church, and enlightened symbolically by the Holy Spirit.

The Tower of Pisa in Rome,Italy (By : Kezia)

The Leaning Tower of Pisa or simply the Tower of Pisa is the campanile, or freestanding bell tower of the cathedral of the Italian city of Pisa, known worldwide for its unintended tilt to one side. It is situated behind the Cathedral and is the third oldest structure in Pisa's Cathedral Square  after the Cathedral and the Baptistry. The tower's tilt began during construction, caused by an inadequate foundation on ground too soft on one side to properly support the structure's weight. The tilt increased in the decades before the structure was completed, and gradually increased until the structure was stabilized  by efforts in the late 20th and early 21st centuries.

The height of the tower is 55.86 m from the ground on the low side and 56.70 m on the high side. The width of the walls at the base is 4.09 m and at the top 2.48 m. Its weight is estimated at 14,500 metric tons. The tower has 294 steps; the seventh floor has two fewer steps on the north-facing staircase. Prior to restoration work performed between 1990 and 2001, the tower leaned at an angle of 5.5 degrees, but the tower now leans at about 3.99 degrees. This means that the top of the tower is displaced horizontally 3.9 metres from where it would be if the structure were perfectly vertical.

Architect

            There has been controversy about the real identity of the architect of the Leaning Tower of Pisa. For many years, the design was attributed to Guglielmo and Bonanno Pisano, a well-known 12th-century resident artist of Pisa, famous for his bronze casting, particularly in the Pisa Duomo. Bonanno Pisano left Pisa in 1185 for Monreale, Sicily, only to come back and die in his home town. A piece of cast with his name was discovered at the foot of the tower in 1820, but this may be related to the bronze door in the façade of the cathedral that was destroyed in 1595. However, recent studies seem to indicate Diotisalvi as the original architect due to the time of construction and affinity with other Diotisalvi works, notably the bell tower of San Nicola and the Baptistery, both in Pisa. However, he usually signed his works and there is no signature by him in the bell tower which leads to further speculation.

Alternative candidates

Two German churches have challenged the tower's status as the world's most lop-sided building: the 15th-century square Leaning Tower of Suurhusen and the 14th century bell tower in the town of Bad Frankenhausen. Guinness World Records measured the Pisa and Suurhusen towers, finding the former's tilt to be 3.97 degrees. In June 2010 Guinness World Records certified the Capital Gate building in Abu Dhabi, UAE as the "World's Furthest Leaning Man-made Tower". The Capital Gate tower has an 18-degree slope, almost five times more than the Pisa Tower; however the Capital Gate tower has been deliberately engineered to slant. The Leaning Tower of Wanaka in New Zealand, also deliberately built, leans at 53 degrees to the ground.

Grand Canyon in Arizona (By : Johanna)

The Ancient Pueblo People were a Native American culture centered on the present-day Four Corners area of the United States. The Ancient Puebloans were the first people to live in the Grand Canyon area. Which there are many chasm. And carved by Colorado river. The cultural group has often been referred to in archaeology as the Anasazi, although the term is not preferred by the modern Puebloan peoples. The word "Anasazi" is Navajo for "Ancient Ones" or "Ancient Enemy".

Archaeologists still debate when this distinct culture emerged. The current consensus, based on terminology defined by the Pecos Classification, suggests their emergence around 1200 BCE, during the archaeologically designated Basketmaker II Era. Beginning with the earliest explorations and excavations, researchers have believed that the Ancient Puebloans are ancestors of the modern Pueblo peoples.

In addition to the Ancestral Puebloans, a number of distinct cultures have inhabited the Grand Canyon area. The Cohonina lived to the west of the Grand Canyon, between 500 and 1200 AD. The Cohonina were ancestors of the Yuman, Havasupai, and Walapai peoples who inhabit the area today.

The Sinagua were a cultural group occupying an area to the southeast of the Grand Canyon, between the Little Colorado River and the Salt River, between approximately 500 AD and 1425 AD. The Sinagua may have been ancestors of several Hopi clans.

By the time of the arrival of Europeans in the 16th century, newer cultures had evolved. The Hualapai inhabit a 100-mile (160 km) stretch along the pine-clad southern side of the Grand Canyon. The Havasupai have been living in the area near Cataract Canyon since 1200 AD, occupying an area the size of Delaware. The Southern Paiutes live in what is now southern Utah and northern Arizona. The Navajo or Diné, live in a wide area stretching from the San Francisco Peaks eastwards towards the Four Corners. Archaeological and linguistic evidence suggests the Navajo descended from the Athabaskan people near Great Slave Lake, Canada, who migrated after 1000 AD.

Plants

There are approximately 1,737 known species of vascular plants, 167 species of fungi, 64 species of moss and 195 species of lichen found in Grand Canyon National Park. This variety is largely due to the 8,000 foot elevation change from the Colorado River up to the highest point on the North Rim. Grand Canyon boasts a dozen endemic plants (known only within the Park's boundaries) while only ten percent of the Park's flora is exotic. Sixty-three plants found here have been given special status by the U.S. Fish and Wildlife Service.

The Mojave Desert influences the western sections of the canyon, Sonoran Desert vegetation covers the eastern sections, and ponderosa and pinyon pine forests grow on both rims.

Natural seeps and springs percolating out of the canyon walls are home to 11% of all the plant species found in the Grand Canyon. The Canyon itself can act as a connection between the east and the west by providing corridors of appropriate habitat along its length. The canyon can also be a genetic barrier to some species, like the Tassel-eared squirrel.

The aspect, or direction a slope faces, also plays a major role in adding diversity to the Grand Canyon. North-facing slopes receive about one-third the normal amount of sunlight, so plants growing there are similar to plants found at higher elevations, or in more northern latitudes. The south-facing slopes receive the full amount of sunlight and are covered in vegetation typical of the Sonoran Desert.

Animals

Of the 34 mammal species found along the Colorado River corridor, 18 are rodents and eight are bats.

Panama Canal (By : Johanna)

The Panama Canal (Spanish: Canal de Panamá) is a 48-mile (77.1 km) ship canal in Panama that connects the Atlantic Ocean to the Pacific Ocean. The canal cuts across the Isthmus of Panama and is a key conduit for international maritime trade. There are locks at each end to lift ships up to Gatun Lake (26 m above sea-level). The Gatun Lake was used to reduce the amount of work required for a sea-level connection. The current locks are 33.5 m wide. A third, wider lane of locks is being built.

France began work on the canal in 1881, but had to stop because of engineering problems and high mortality due to disease. The United States later took over the project and took a decade to complete the canal in 1914, enabling ships to avoid the lengthy Cape Horn route around the southernmost tip of South America (via the Drake Passage) or to navigate the Strait of Magellan. One of the largest and most difficult engineering projects ever undertaken, the Panama Canal shortcut made it possible for ships to travel between the Atlantic and Pacific Oceans in half the time previously required. The shorter, faster, safer route to the US West Coast and to nations in and along the Pacific Ocean allowed those places to become more integrated with the world economy.

During this time, ownership of the territory that is now the Panama Canal was first Colombian, then French, and then American; the United States completed the construction. The canal was taken over in 1999 by the Panamanian government, as long planned. Annual traffic has risen from about 1,000 ships when the canal opened in 1914, to 14,702 vessels in 2008, the latter measuring a total of 309.6 million Panama Canal/Universal Measurement System  tons. By 2008, more than 815,000 vessels had passed through the canal, many of them much larger than the original planners could have envisioned; the largest ships that can transit the canal today are called Panamax. The American Society of Civil Engineers has named the Panama Canal one of the seven wonders of the modern world.

Efficiency and maintenance

Opponents to the 1977 Torrijos-Carter Treaties feared that efficiency and maintenance would suffer following the U.S. withdrawal from the Panama Canal Zone; however, this does not appear to have been the case. Capitalizing on practices developed during the American administration, canal operations are improving under Panamanian control. Canal Waters Time, the average time it takes a vessel to navigate the canal, including waiting time, is a key measure of efficiency; according to the ACP, since 2000, it has oscillated between 20 and 30 hours. The accident rate has also not changed appreciably in the past decade, varying between 10 and 30 accidents each year across approximately 14,000 total annual transits. An official accident is one in which a formal investigation is requested and conducted.

Increasing volumes of imports from Asia, which previously landed on U.S. West Coast ports, are now passing through the canal to the American East Coast. The total number of ocean-going transits increased from 11,725 in 2003 to 13,233 in 2007, falling to 12,855 in 2009. (The canal's fiscal year runs from October through September.) This has been coupled with a steady rise in average ship size and in the numbers of Panamax vessels passing through the canal, so that the total tonnage carried rose from 227.9 million PC/UMS tons in fiscal year 1999 to a record high of 312.9 million tons in 2007, falling to 299.1 million tons in 2009. Despite the reduction in total transits due to the negative impact of vessel size (e.g., the inability of large vessels to pass each other in the Gaillard Cut), this represents significant overall growth in canal capacity.

The Panama Canal Authority (ACP) has invested nearly US$1 billion in widening and modernizing the canal, with the aim of increasing capacity by 20%. The ACP cites a number of major improvements, including the widening and straightening of the Gaillard Cut to reduce restrictions on passing vessels, the deepening of the navigational channel in Gatun Lake to reduce draft restrictions and improve water supply, and the deepening of the Atlantic and Pacific entrances to the canal. This is supported by new equipment, such as a new drill barge and suction dredger, and an increase of the tug boat fleet by 20%. In addition, improvements have been made to the canal's operating machinery, including an increased and improved tug locomotive fleet, the replacement of more than 16 km of locomotive track, and new lock machinery controls. Improvements have been made to the traffic management system to allow more efficient control over ships in the canal.

In December 2010, record-breaking rains caused a 17-hour closure of the canal; this was the first closure since the United States invasion of Panama in 1989. The rains also caused an access road to the Centenario bridge to collapse.

Burj Khalifa in Dubai, United Arab Emirates (By : Kezia)

          Burj Khalifa, known as Burj Dubai prior to its inauguration, is a skyscraper in Dubai, United Arab Emirates, and is the tallest man-made structure in the world, at 829.8m.

Construction began on 21 September 2004, with the exterior of the structure completed on 1 October 2009. The building officially opened on 4 January 2010, and is part of the new 2 km2 development called Downtown Dubai at the 'First Interchange' along Sheikh Zayed Road, near Dubai's main business district. The tower's architecture and engineering were performed by Skidmore, Owings and Merrill of Chicago, with Adrian Smith as chief architect, and Bill Baker as chief structural engineer. The primary contractor was Samsung C&T of South Korea.

In March 2009, Mohamed Ali Alabbar, chairman of the project's developer, Emaar Properties, said office space pricing at Burj Khalifa reached US$4,000 per sq ft and the Armani Residences, also in Burj Khalifa, sold for US$3,500 per sq ft. He estimated the total cost for the project to be about US$1.5 billion.

The project's completion coincided with the global financial crisis of 2007–2012, and with vast overbuilding in the country; this led to high vacancies and foreclosures. With Dubai mired in debt from its huge ambitions, the government was forced to seek multibillion dollar bailouts from its oil-rich neighbor Abu Dhabi. Subsequently, in a surprise move at its opening ceremony, the tower was renamed Burj Khalifa, said to honour the UAE President Khalifa bin Zayed Al Nahyan for his crucial support.

Because of the slumping demand in Dubai's property market, the rents in the Burj Khalifa plummeted 40% some ten months after its opening. Out of 900 apartments in the tower, 825 were still empty at that time. However, over the next two and a half years, overseas investors steadily began to purchase the available apartments and office space in Burj Khalifa. By October 2012, Emaar reported that around 80% of the apartments were occupied.

Conception

Burj Khalifa was designed to be the centerpiece of a large-scale, mixed-use development that would include 30,000 homes, nine hotels, 3 hectares of parkland, at least 19 residential towers, the Dubai Mall, and the 12-hectare man-made Burj Khalifa Lake.

The building has returned the location of Earth's tallest freestanding structure to the Middle East, where the Great Pyramid of Giza claimed this achievement for almost four millennia before being surpassed in 1311 by Lincoln Cathedral in England.

The decision to build Burj Khalifa is reportedly based on the government's decision to diversify from an oil based economy to one that is service and tourism based. According to officials, it is necessary for projects like Burj Khalifa to be built in the city to garner more international recognition, and hence investment. "He (Sheikh Mohammed bin Rashid Al Maktoum) wanted to put Dubai on the map with something really sensational," said Jacqui Josephson, a tourism and VIP delegations executive at Nakheel Properties.

Giant Wall in China (By : Kezia)

The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China in part to protect the Chinese Empire or its prototypical states against intrusions by various nomadic groups or military incursions by various warlike peoples or forces. Also known as Wall Along the 10000 Li. Several walls were being built as early as the 7th century BC; these, later joined together and made bigger, stronger, and unified are now collectively referred to as the Great Wall. Especially famous is the wall built between 220–206 BC by the first Emperor of China, Qin Shi Huang. Little of that wall remains. Since then, the Great Wall has on and off been rebuilt, maintained, and enhanced; the majority of the existing wall was reconstructed during the Ming Dynasty. This is a UNESCO World Heritage Site

Other purposes of the Great Wall have included border controls, allowing the imposition of duties on goods transported along the Silk Road, regulation or encouragement of trade and the control of immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of watch towers, troop barracks, garrison stations, signaling capabilities through the means of smoke or fire, and the fact that the path of the Great Wall also served as a transportation corridor.

The Great Wall stretches from Shanhaiguan in the east, to Lop Lake in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. A comprehensive archaeological survey, using advanced technologies, has concluded that the Ming walls measure 8,851 km. This is made up of 6,259 km sections of actual wall, 359 km of trenches and 2,232 km of natural defensive barriers such as hills and rivers. Another archaeological survey found that the entire wall with all of its branches measure out to be 21,196 km.

Characteristics

Before the use of bricks, the Great Wall was mainly built from rammed earth, stones, and wood. During the Ming Dynasty, however, bricks were heavily used in many areas of the wall, as were materials such as tiles, lime, and stone. The size and weight of the bricks made them easier to work with than earth and stone, so construction quickened. Additionally, bricks could bear more weight and endure better than rammed earth. Stone can hold under its own weight better than brick, but is more difficult to use.Consequently, stones cut in rectangular shapes were used for the foundation, inner and outer brims, and gateways of the wall. Battlements line the uppermost portion of the vast majority of the wall, with defensive gaps a little over 30 cm tall, and about 23 cm wide.

Condition

While some portions north of Beijing and near tourist centers have been preserved and even extensively renovated, in many locations the Wall is in disrepair. Those parts might serve as a village playground or a source of stones to rebuild houses and roads. Sections of the Wall are also prone to graffiti and vandalism. Parts have been destroyed because the Wall is in the way of construction.

More than 60 km of the wall in Gansu province may disappear in the next 20 years, due to erosion from sandstorms. In places, the height of the wall has been reduced from more than five meters to less than two meters. The square lookout towers that characterize the most famous images of the wall have disappeared completely. Many western sections of the wall are constructed from mud, rather than brick and stone, and thus are more susceptible to erosion. In August 2012, a 30 metre section of the wall in north China's Hebei province collapsed after days of continuous heavy rains.

Hanging Gardens in Babylon (By : Kezia)

The Hanging Gardens of Babylon were one of the Seven Wonders of the Ancient World, and the only one of the wonders that may have been purely legendary. They were purportedly built in the ancient city-state of Babylon, near present-day Al Hillah, Babil province, in Iraq. The Hanging Gardens were not the only World Wonder in Babylon; the city walls and obelisk attributed to Queen Semiramis were also featured in ancient lists of Wonders.

The gardens were attributed to the Neo-Babylonian king Nebuchadnezzar II, who ruled between 605 and 562 BC. He is reported to have constructed the gardens to please his homesick wife Amytis of Media, who longed for the plants of her homeland. The gardens were said to have been destroyed by several earthquakes after the 2nd century BC. The Hanging Gardens of Babylon are documented by ancient Greek and Roman writers, including Strabo, Diodorus Siculus, and Quintus Curtius Rufus. However, no cuneiform texts describing the Hanging Gardens are extant, and no definitive archaeological evidence concerning their whereabouts has been found.

Ancient writers describe the possible use of an Archimedes screw-like process to irrigate the terraced gardens. Estimates based on descriptions of the gardens in ancient sources say the Hanging Gardens would have required a minimum amount of 8,200 gallons (37,000 litres) of water per day. Nebuchadnezzar II is reported to have used massive slabs of stone, a technique not otherwise attested in Babylon, to prevent the water from eroding the ground.

Scholarship and controversy

         There is some controversy as to whether the Hanging Gardens were an actual construction or a poetic creation, owing to the lack of documentation in contemporaneous Babylonian sources. There is also no mention of Nebuchadnezzar's wife Amyitis (or any other wives), although a political marriage to a Median or Persian would not have been unusual. Herodotus, writing about Babylon closest in time to Nebuchadnezzar II, does not mention the Hanging Gardens in his Histories. However, it is possible that cuneiform texts on the Hanging Gardens may yet be found.

         To date, no archaeological evidence has been found at Babylon for the Hanging Gardens. It is possible that evidence exists beneath the Euphrates, which cannot be excavated safely at present. The river flowed east of its current position during the time of Nebuchadnezzar II, and little is known about the western portion of Babylon.

         A recent theory proposes that the Hanging Gardens of Babylon were actually constructed by the Assyrian king Sennacherib (reigned 705 – 681 BC) for his palace at Nineveh. Stephanie Dalley posits that during the intervening centuries the two sites became confused, and the extensive gardens at Sennacherib's palace were attributed to Nebuchadnezzar II's Babylon.