Inside Beijing’s 2008 Olympic swimming complex.

Appropriately, some of the building’s most innovative features are its systems for handling water. Unlike most swimming pools, which send filter backwash water to the municipal wastewater systems, the Water Cube collects such gray water for treatment and returns it to the pool. The system substitutes rainwater collected from the roof for the small amount of gray water lost in the treatment process. The strategy lessens the burden of the building on Beijing’s wastewater infrastructure and makes it less dependent on the city’s already constrained fresh-water supply. “The idea was to make it as self-sufficient as possible,” says Carfrae.

Read more about this fascinating building’s passive heat systems, bubble physics and rad ventilation systems.