On Jan. 4, 2009, Burj Khalifa, a.k.a. Burj Dubai, the world's tallest man-made structure, officially opened. Here's a look at the buildings that have claimed that _title_ in the past. [image: http://img.timeinc.net/time/photoessays/2009/tall_buildings/tall_buil...] * Burj Dubai * Dubai may be struggling financially, but money problems didn't keep it from opening Burj Dubai on Jan. 4 and snagging the _title_ for world's tallest building from Toronto, which has the soon-to-be second tallest CN Tower. Burj Dubai's actual height is a closely guarded secret, although developers admit that it will be at least 2,600 ft. (790 m) tall — almost twice the height of Chicago's Willis Tower. The tower, which cost an estimated $1.5 billion to construct, boasts 164 floors, nearly 1,100 one- to three-bedroom apartments and elevators that travel up to 25 m.p.h. (40 km/h) Visitors to the 124th-floor observation deck can see 50 miles (80 km) on a clear day. [image: http://img.timeinc.net/time/photoessays/2009/tall_buildings/tall_buil...] The Great Pyramid Humanity's edifice complex goes back — way back — to around 2,575 B.C., when the Great Pyramid of Giza, the tallest of Egypt's famous monuments, began its four-millennium reign as the world's tallest building. Originally rising 481 ft. (146 m) above a rocky stretch along the Nile river, it has been beaten down 30 ft. (9 m) by years of erosion. [image: http://img.timeinc.net/time/photoessays/2009/tall_buildings/tall_buil...] Lincoln Cathedral Lincoln Cathedral has taken its share of beatings — a fire around 1141, an earthquake in 1185 and a collapse of its central tower in the 1230s. But at 524 ft. (160 m), the house of worship in northwestern England held the _title_ of world's tallest building for more than 200 years, until 1549. The building, regarded as one of the largest and most magnificent churches in all of Europe, was started in the 11th century and took literally centuries to complete. The lead-covered spire built in the 14th century made it the tallest building in Europe, a _title_ it lost when the spire collapsed in 1549. Even without the spire, however, it remains the tallest cathedral in Europe. [image: http://img.timeinc.net/time/photoessays/2009/tall_buildings/tall_buil...] Cologne Cathedral In the early 14th century, churches began a long period of dominance as the world's tallest structures. Entrants from Estonia, France and Germany all vied for the _title_ over the ensuing centuries. St. Olaf's in Tallinn succeeded Lincoln Cathedral in 1549, and held the designation until 1625, when its spire burned down after a lightning strike. Houses of worship in Germany (Stralsund, Hamburg) and in Rouen and Strasbourg in France swapped the world's-tallest _title_ until 1880, when Cologne Cathedral, which checked in at a towering 518 ft. (157 m), took over the honor after a laborious construction process that lasted more than six centuries. The German church, which survived bombing campaigns in World War II and became a World Heritage site in 1996, owned the designation for just four years, when the newly completed Washington Monument surpassed it. [image: http://img.timeinc.net/time/photoessays/2009/tall_buildings/tall_buil...] The Washington Monument Towering above Washington, D.C., at just over 555 ft. (169 m) is the Washington Monument — a tribute to the nation's first President and his military prowess during the Revolutionary War. Architect Robert Mills' conception of a neoclassical rotunda topped by a towering obelisk won the competition to design the monument; construction started in 1848. A lack of funds, haphazard organization and the outbreak of the Civil War caused several delays, however, and by the time construction started up again, architectural tastes and _style_s had changed and Mills had passed away. His original design was heavily altered and an unadorned, pointed Egyptian obelisk prevailed — thanks in part to George P. Marsh, the U.S. ambassador to Italy and a design adviser for the monument, who had spent time living in Egypt and was influenced by the many Egyptian obelisks scattered throughout Rome. By 1884 the structure was complete; today, visitors who take an elevator to the top can enjoy unobstructed, 30-mile (48 km) views of the U.S. capital. [image: http://img.timeinc.net/time/photoessays/2009/tall_buildings/tall_buil...] The Eiffel Tower The French don't brag about the Eiffel Tower's height (984 ft., or 300 m) but they do like to remind admirers of the structure that when it was erected in 1889, it was twice as high as the dome of St. Peter's Basilica in Rome and the Great Pyramid of Giza. Not only that, but it was also built in two years with a small labor force of just 300 workers, at the minimal cost of about $1.5 million. It opened in time to serve as the entrance gate for the International Exposition (or World's Fair) of 1889. It stood as the world's tallest building until 1930, when New York City's Chrysler Building edged it out, but it certainly remains one of the most efficient. [image: http://img.timeinc.net/time/photoessays/2009/tall_buildings/tall_buil...] Chrysler Building Iconic as it is, New York City's Chrysler Building enjoyed the _title_ of world's tallest building for barely a year. It began its reign in late 1929, after winning a heated competition with the developers of the Bank of Manhattan Trust building (now known as 40 Wall Street) who had publicly declared their tower to be tallest in the world before completion. The Chrysler Building's designers secretly constructed a 180-ft. (55 m) spire within its main tower; when it was hoisted into position, the Art Deco masterpiece topped out at 1,046 ft. (319 m). However, its reign was already doomed: the Empire State Building, under construction a few blocks south, would dwarf it upon opening in 1931. [image: http://halmasonberg.files.wordpress.com/2009/10/empire-state-building...] Empire State Building It has been hit by a plane, it has been climbed by a giant gorilla (in both film and real life: an inflatable gorilla was attached to its side for the 50th anniversary of the original movie *King Kong* in 1983) and it has twice stood as New York City's tallest building (before the World Trade Center's completion in 1972 and after its destruction on Sept. 11, 2001). At 102 stories, the Empire State Building has become one of the world's most iconic structures and landmarks. In 1967, after having held the _title_ of world's tallest building since 1931, it was surpassed by the Ostankino Tower in Moscow. [image: http://www.guesstheplace.net/data/item-135.jpg] Ostankino Tower In 1967, Moscow joined the tall-building competition when it unveiled the Ostankino Tower, a 1,772-ft. (540 m) monument to mark the 50th anniversary of the Bolshevik Revolution. It held the tallest _title_ for nine years until Canada finished its CN Tower in 1976. Technically, Chicago's Sears Tower — the 110-story skyscraper built in 1974 and recently renamed the Willis Tower — has more inhabitable floors (visitors can ascend 1,450 ft. [440 m] in Chicago but only 1,180 ft. [360 m] in Moscow) but Ostankino Tower's spire makes it roughly 30 ft. (9 m) higher. [image: http://www.isprogram.utoronto.ca/images/gallery/toronto/CN-Tower-and-...] CN Tower Stretching more than 1,800 ft. (550 m) into the air is CN Tower — the tallest freestanding structure in the Americas and one of the modern Seven Wonders of the World. The tower — built by Canadian National Railway — was designed as a telecommunications hub to overcome the problem of poor reception caused by Toronto's skyscrapers. After its completion in 1976, the tower also became a downtown tourist attraction, and today more than 2 million visitors enjoy multiple observation decks, cafés and even a 360-degree revolving restaurant each year. * *