In the heart of Tirana, this underground nuclear bunker has been transformed into a museum.

A museum dedicated to secret surveillance.

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

What happens when you cross a mayor and a painter?

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

An Albanian monument to the Communism that nearly crushed the country is now a crumbling wreck.

The tallest minaret in Yemen is 150 feet high and entirely made of mud.

One of the largest mud-brick structures in the world.

This impressive system of tanks was used to store drinking water as long as 2,000 years ago.

A city built from mud and known as the "Manhattan of the desert."

An idyllic traditional timber village on a picturesque hill was built for a film.

A monument on the pavement marks the spot where two cultures that shaped Sarajevo come together.

The first mosque in the world to receive electricity.

This historic timepiece is thought to be the only public clock in the world that keeps lunar time.

Celebrated example of Ottoman architecture that also served as a site for brutal massacres.

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

Oriental bazaar in the heart of Sarajevo.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.

Inspired by the Rialto Bridge in Venice, these three clustered bridges were just one part of a Slovenian architect’s grand vision.

With a 90-foot wingspan, the world’s largest loon sculpture stands outside Allianz Field.

This staircase full of Mayan hieroglyphics is perhaps the largest single text in the world.

A Mayan village preserved for centuries in volcanic ash.

This color-changing crater lake in El Salvador is occasionally impenetrable to sunlight.

This U.S. natural reserve is an ancient spiritual place and rock climber’s paradise.