This network of tunnels housed an entire village for years, and even had a hall for screening movies.

Monument to a brutal, ineffectual US bombing campaign and a sobering reminder of the human cost of the Vietnam War.

The spot where the two men ate together now stands enclosed in glass.

Edison's cast-in-place concrete houses were a failure, but way ahead of their time.

A crumbling mountain resort that looks like it was abandoned in an instant.

This marvelous work of outsider architecture is built into the cliffs of an Israeli beach.

This top secret Chinese military megaproject is the world’s largest human-made tunnel structure.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Morocco's Argania trees are infested with nut-hungry goats.

A massive, abstract lookout tower providing a panoramic view of Prague.

The hidden lair of an alchemist rediscovered in a 2002 flood.

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.

This derelict superstructure was a very important warning system for the Soviet military.

The dining hall that nourishes workers in Chernobyl's Exclusion Zone is also open to visitors.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

An abandoned outdoor movie theater in the Sinai desert.

The forgotten mummies of Dakhla oasis.

Slum Settlement Filled With Mountains of Garbage.

Crammed inside this grounded passenger plane is a bar that was once a Communist hang out and is now a ratty relic.

One of the famous Czech artist's lesser-known Prague installations appears to be a glowing fetus affixed to a drainpipe.

The last municipal pneumatic post system in the world was in operation for over 100 years, and may run again.

The world's greatest slide descends 18 stories from this looping mountaintop viewing platform.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.