There’s an age old adage that says you’re never more than six feet away from a rat in any urban setting. What people aren’t so aware of is exactly where those rodents may be hiding. In the case of many towns and cities the world over, the streets we walk along are as little as six feet above some truly amazing and ingenious tunnel systems. Some are still in use, some have strange histories, and the very existence of some remains a mystery.

Come along as John Reppion sheds light on overlooked gems in London, Moscow, New York, Indianapolis, Paris, and more! 

Atlas Obscura presents its ESSENTIAL GUIDE: Hidden Tunnels of Urban Infrastructure!