World's largest building: The New Century Global Center officially opens in China

The building is so large it is capable housing 20 Sydney Opera Houses and is almost three times the size of the Pentagon in Washington, D.C.

The numbers are little short of staggering; at 500 metres long, 400 metres wide and 100 metres high a 1.76-million-square-metre-mega-building has been opened in Sichuan province in southwestern China.

The New Century Global Center, officially the largest freestanding building in the world, took three years to complete and will house offices, shopping malls, a Mediterranean village, a 14-screen IMAX Cineplex and an ice-skating rink large enough to hold international skating competitions.

The building is so large it is capable of housing the equivalent of 20 Sydney Opera Houses and is almost three times the size of the Pentagon in Washington, D.C.

At the centre of the building is a huge water park called Paradise Island. Around 400,000 square metres of the building are dedicated to shopping.

The building sits directly opposite the Chengdu Contemporary Arts Centre, designed by British-Iraqi architect Zaha Hadid.

The New Century Global Center is at the heart of a new planned area of Chengdu, the capital of Sichuan province in southwestern China.

Its opening has been timed to coincide with the expansion of a new subway line for the area and the planned construction of a new airport set for completion in 2020.