Officially named The Metropolitan Area Outer Underground Discharge Channel, it’s the largest storm drain in the world. Completed in 2006, the anti-flood system lies 165 feet (about 50 meters) below Kasukabe City in Saitama Prefecture, is made up of a network of five silos connected by four miles of tunnels, and cost a reported US$2 billion to construct. It’s a modern feat of engineering that’s out of sight and out of mind, but one day it may save lives and prevent a whole lot of damage.

For a closer look at this incredible feat of modern engineering, as well as information on how to visit, read the full article at Spoon & Tamago via the link below.