Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Baroque celebration of the end of the Great Plague of Vienna.

Legends surround an ancient tree trunk riddled with nails for good luck.

The beautiful baroque library of the Hapsburg empire.

One of the world's oldest olive trees, thought to be over 2,000 years old.

A curious cave church carved into the face of a cliff.

The romantic garden was the epicenter of the Hungarian art scene in the 1880s.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Gargoyle head that brings good luck.

A wonderfully strange collection of 500+ stuffed frogs doing people things.

An ethereal glowing blue ocean cave in Croatia.

Once the home of a hermetic monk, this cave now houses a small church.

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

A Jenga-style cylindrical tower of books that appears to go on forever.

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

The first museum in the world devoted to sexual gadgetry.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.