Edogawa River Project (Tokyo, Japan)
With Tokyo in the path of as many as two dozen typhoons each year, the city and its 12 million inhabitants are continually endangered by flooding. The answer: one of the most massive pumping systems ever constructed. Begun in 1992, with completion scheduled for 2009, the $2 billion system includes a four-mile-long network of tunnels connected to an 83-foot-tall storage tank and a cathedral-like structure of 59 massive pillars. The system's powerful turbines can pump 200 tons of water into the Edogawa River each second. The system has become a Tokyo tourist attraction, and it also has been used by television and movie crews as an eerily dramatic backdrop.