What is the tallest concrete building in the world?
The tallest free-standing structure in the world is the CN Tower in Toronto, Canada. This stands at 554 metres. However it is argued that the CN Tower is not really a building even though it has a restaurant and observation tower. The tallest building in the world is currently the Taipai 101 tower in Taipei, Taiwan. Completed in 2004, this tower rises to 509 meters, and has 101 floors. Both the CN Tower and Taipei 101 were constructed in concrete.