17th century streets hidden under Edinburgh were once a breeding ground for the black death.

The 16th-century church has the only stained glass windows that survived the Scottish Reformation intact.

This controversial depiction of the "Founder of California" looks as though it was sculpted from mashed potatoes.

This unique formation appears as though an asteroid landed on the forest.

The world’s first stop-motion film was created on the racetrack outside this building.

A classically inspired temple in Redwood City.

Not-so-fearsome tiny trolls live under this wooden train trestle in Portland.

Nine bronze hands protruding from a wall honor the student uprising that led to the fall of Czechoslovakia's Communist government.

An existential riddle in the world's largest ancient castle.

Two stunning 17th-century libraries and a cabinet of curiosities.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

Thousands of effigies of Buddha watch from caves set high above a legendary river, plus whiskey.

The wartime boat shelter now doubles as an underground concert hall where musicians play on rafts along the waterway.

Monks turned this mountain into a temple by digging grottoes, tunnels, and a huge pagoda-like hall.

Comprised of thousands of cave temple carvings this cornucopia of ancient Chinese stone art is unrivaled anywhere in the world.

A bright turquoise river cascades beautifully down stepped terraces in southern China.

Described as "the world's most blinging pool."

This terrifying glass bridge on the side of a mountain cracks as you step on it.

China's very own Atlantis is an ornate dynastic city resting at the bottom of a lake.

A cliff-hanging restaurant.

A church of bones, decorated with 40,000 human skeletons.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

This charming wooden church was disassembled and moved not once but twice before settling in this Prague garden.

Mummified monks and the accidentally interred, in a 17th-century crypt.