Tokyo's underground holds a fantastic infrastructure, whose look is similar to that of a computer game or a temple from a remote civilization. Five wells with a 32-metre diameter and a 65-metre depth are interlinked by 64 km of tunnels that come together to form a colossal draining system for pluvial water, with the goal of preventing the city from floods during the rainy season.
The size of this underground complex defies all imagination. It's a state of the art work of engineering, in concrete, located 50 metres below the ground, something extraordinary for a country that is constantly subject to earthquakes and whose main infrastructures are aerial. Its function is not only to store the water, but also evacuate it to the nearest river, should it be necessary. For that, it has a 14 000 Hp worth of turbines, able to pump, outside, about 200 t of water per second. Impressive.