French daredevil climber Alain Robert dressed like Spiderman gives the thumbs up as he climbs a 32-story building in business district La Defense, outside Paris, on June 18, 2002. Robert has climbed more than 30 skyscrapers over the world.
A view of Tokyo Skytree, the world's tallest broadcasting tower at 634 meters (2080 feet), in Tokyo on May 21, 2012. The tower opened to the public on May 22, with hundreds of people entering the tower and its large shopping mall.
People place LED lights to form a 'No CO2' slogan in support of global efforts to reduce greenhouse gases during the Earth Hour Saturday, in Taipei, Taiwan. More than 20 high-rise buildings in Taiwan's capital dimmed their lights for an hour in a gesture against global warming.
The Burj Khalifa, the world's tallest tower, is pictured in Dubai on Jan. 3. The Gulf emirate inaugurated on the world's tallest tower, a symbol of its unbridled ambitions of recent years, on Jan. 4 amid continuing fears over cash problems facing the emirate which narrowly escaped a financial catastrophe last month.
From the last-minute name change to the engineering feats involved in constructing the world's tallest building, the Burj Khalifa continues to generate a buzz.
The world's tallest buildings usually open when the economy has crashed, just like Monday's opening of the Burj Khalifa in Dubai.
Spectators watch a traditional pig race at the Swiss agriculture fair OLMA in St. Gallen, Switzerland, on Thursday.