The underground cathedral protecting Tokyo from floods (2018)
When one of these rivers overflows, the water falls to one of five enormous 70-meter tall cylindrical tanks spread across the Channel’s length. Each of these tanks is big enough to accommodate a space shuttle or the Statue of Liberty and they are interconnected through a 6.3km long network of underground tunnels. As the water approaches the Edo River, the ‘floodwater cathedral’ Tortajada visited reduces its flow, so the pumps can push it to the river.