Metropolitan Area Outer Underground Discharge Channel
Metropolitan Area Outer Underground Discharge Channel is the world's largest underground drainage channel that takes floods of medium and small rivers that have overflowed into the basement and flows to the Edogawa through a tunnel with a total extension of 6.3 kilometers underground at 50 meters. Therefore, it is an underground river and at the same time has a function as a huge flood control pond. It is designed not to be damaged by seismic intensity 7 earthquakes. This tunnel was completed in 2006 with an extension of about 6.3 km and an inside diameter of about 10 m. The state of 59 giant concrete pillars of 18 meters in height and 500 tons in height arranged in this giant aquarium space stands as if it is an underground temple. Since it is in the airborne condition without taking in water normally, it is a huge underground space where people can enter. For some of the facilities, if you make a reservation you can visit general except at the time of flooding.