A relic of World War I that now exist as a piece of public art.

This hidden art nouveau gem was designed by an architect in search of a national style.

Electrical curiosity museum housed in an old transformer station.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

If there's another drive-through golf-cart bar in a bat-filled cave on top of a mountain, we don't know about it.

A deadly ancient portal to the underworld.

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

A picture-perfect town, perfect for blowing up.

The site where a nuclear bomb was lowered over 8,000 feet underground and detonated as an experiment in natural gas extraction.

A facility built in 1992 for an underground nuclear test remains in place today.

The largest man-made crater in the U.S. marks the spot where we once tested mining with nukes.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

According to myth, Zeus himself was hidden in this cave to escape being eaten by his dad.

This former Cyprus flight hub is now a crumbling, abandoned ghost complex.

This work of engineering is imbued with elegance and ingeniousness.

Largest institutional collection of tomb figures from Western Mexico in the United States.

A showcase of geologic history is home to one of the largest collection of lunar meteorites on Earth.

A restored historic movie theater is the perfect place for a regional film archive.

This uninhabited island in Maine is home to various works of art left by visitors over the years.

Explore the dark underground corridors of this graffiti-covered former military fortification.

This is one really big nut.

Wars fought and wars won are remembered by these abandoned bunker ruins.

Once a major stop on the Hejaz Railway, this desert station (complete with steam locomotive) has been abandoned for decades.

A 2017 crowdfunding campaign saved this historic castle from being destroyed.