Tunnels

An ancient tunnel in Jerusalem built to redirect water in the event of a siege is one of history’s great architectural innovations.

This railroad tunnel was once the longest in Massachusetts.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

Railways may have forged this quintet of lovely tunnels, but now they are open to hikers.

A railroad tunnel that, upon its completion, was considered one of the engineering marvels of the modern world.

A naturally occurring tunnel in this Nordic mountain makes it look like it's been shot.

A little-known subterranean street runs under some of the best-known buildings in Chicago's River North.

These World War I shooting range tunnels are now haunted halls of underground graffiti accessed through the roots of a tree.

This psychedelic tourist trap is a leisurely descent into madness.