Che sez:
Tokyo is an impressive city above ground, but one of the most incredible things about this city is it's mind-bogglingly complex underground. The G-Cans Project is a massive project, begun 12 years ago, to build infrastructure for preventing overflow of the major rivers and waterways spidering the city (A serious problem for Tokyo during rainy-season and typhoon season). The underground waterway is the largest in the world and sports five 32m diameter, 65m deep concrete containment silos which are connected by 64 kilometers of tunnel sitting 50 meters beneath the surface.
The whole system is powered by 14000 horsepower turbines which can pump 200 tons of water a second into the large outlying edogawa river. I'm in the middle of playing Halflife2 right now and something like this looks like its straight out of the game or some sci-fi movie. This unbelievable gallery of photos however, is not CG, it is the real deal.
The site is all in Japanese, but if you click around the menus a bit, there are animations and diagrams of how the system works, and other interesting photos of the high-tech control center and turbine facilities. Supposedly the G-Cans project is also meant to be a tourist attraction, and can be visited for free. very cool. Link
