Prodigy
At 1500ft (450m) high, the Crystal Island project won't be the tallest piece of architecture on the planet, but covering 27 million sq ft (2.5 million sq. m) of floor space, it will be gimungeous.

Basically, the structure in Moscow will be a city within a building and will have its own weather system. London's prestigious Foster + Partners have designed the mega-structure incorporating solar and wind energy systems, making it eco-friendly.

The $4 billion dollar structure that looks like an enormous crystal Christmas tree will have 3,000 hotel rooms and 900 apartment units. Other amenities include an international school, a theater, cinemas and a sports center.

For comparison, the Burj Dubai, the structure that holds the record for world's tallest building (810+m) for the foreseeable future will contain about 3,595,100 sq ft (334,000 m²) when completed. So, the Crystal Island project will have 7.5 times the indoor space.

It's expected to be completed between 2012 and 2013.