Cave on extinct volcano, once home to famous mathematician Pythagoras.

An ornate abandoned schoolhouse hidden in the woods near a decaying mill town.

During the American Revolutionary War, iron excavated from this mine was used to make swords, cannons, and more.

A abandoned hostel which was once home to Brunei's brightest students and present-day politicians.

This former psychiatric hospital was once one of the largest in Australia.

This defunct, fortress-like prison has been the setting for several movies.

One man has spent decades faithfully constructing this unique brick and cinderblock castle.

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

A hidden piece of Altoona's railroad history in a long-forgotten abandoned town.

The ruined remains of a coal mining ghost town are hidden within the woods.

Hidden in the hills of Western Pennsylvania lies one of the best-kept ghost towns in America that you can legally visit.

The Thai Army has dug deep trenches along the Thai/Myanmar border to prevent drug smuggling.

An underwater temple submerged for 20 years has resurfaced with an extreme drought.

In Phetchaburi, Thailand, a roadside vendor cooks his fare with 1,000 mirrors and the power of the sun.

This elephant kraal is the only one remaining in Thailand, dating back to the 16th century when these massive mammals were integral players in war and trade.

The 18th-century inspiration behind Harry Potter's Sorting Hat.

Buddhist university that allows English-language speakers the opportunity to study with monks in Thailand.

Founded during the Ayutthaya era, this unique Buddhist temple remains shipshape to this day.

An amalgam of precariously balanced boulders, ancient petroglyphs, and Buddhist shrines.

Parts of this sprawling temple complex are deteriorating, but its founder’s body remains intact.

This Khmer-era temple includes a lintel that was stolen and displayed at the Art Institute of Chicago for years before returning to Thailand.

A shrine honoring a legendary ghost bride lies within this vibrant temple.

This mountain sunrise is one of the most breathtaking views in Thailand, yet well off the tourist trail.

This serene bamboo walkway allows Buddhist monks from remote temples access to the nearby village.