Plant beds and ponds shaped like fish scales form part of a water purification system in the Chengdu Case Pavilion at the Expo, Aug 8, 2010. The artificial wetland, with dozens of different kinds of plants, filtrates and purifies 15 tons of sewage each day. The Chengdu Case Pavilion is a miniature version of Chengdu's Living Water Park, a system that naturally cleans water from the city's Funan River using water rehabilitation systems. [Photo/Xinhua]

The pond at the entrance to the fish-like Chengdu Case Pavilion saves rainwater and sewage from nearby pavilions. Water flows into the scale-like artificial wetland after six to eight hours' sedimentation. [Photo/Xinhua]