Khmer Rouge's high security prison.

5,000 skulls in memorial to those killed by the Khmer Rouge.

The headquarters of the Mahanikai school of Buddhism, Thailand's largest monastic order.

A condom-covered Thai restaurant that is more concerned with birth control than food.

A treasure trove of pathological, forensic, parasitological, and anatomical specimens.

Bangkok's men with dangerous jobs come here in search of protective talismans.

Hear the quietest sound from across the dome.

Rebuilt remains of a temple to Roman god Mithras.

Scattered throughout London are ancient remnants of the city's former bounding wall.

The quiet field that inspired one of the most famous songs of all time.

Gutted during the Liverpool Blitz, this architectural husk has been left destroyed in honor of the dead.

This Welsh village gave itself a ridiculous name in a publicity stunt a century ahead of its time.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

Northern Ireland's Brobdingnagian stepping stones.

A museum marks and documents the site of the Titanic's launch.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

A peace symbol in Northern Ireland is among the world's largest hedge mazes.

A hugely vast Irish landscape of barren rock that stretches for miles.

The ancient tomb acts as a calendar that keeps perfect time.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

The first U.S. town to secede from the Union, only to vote themselves right back in.

This whimsical seashell-shaped place of worship was designed to blend into its surroundings.

Offering commanding views of the California coastline, this restaurant was a hub for the artists and bohemians of Big Sur.

A popular tourist cave with a dark past.