Foster and Partners is changing the Moscow skyline with this 2,009 feet, what will be the tallest tower in Europe. The Moscow Tower will be completed in 2012, with 118 floors of retail, hotel, office, and residential spaces. About 38% of floor space will be underground. This amount of square footage underground poses a challenge for light and venillation. A natural ventillation system runs a hot water circuit through the builing to regulate temperatures. The three-armed pyramid shape gives more access to light, and skygardens provide a natural, healthy element to the super-structure.