A fairytale-like medieval church perched atop a rocky cliff on Italy's "Coast of the Gods."

Italian cave with exceptional acoustics and an unsavory history.

The world's most active stratovolcano is almost always erupting.

Why a column on the entrance is inscribed with a verse from the Quran is one of Sicily's many mysteries.

Every inch of this chapel is covered in craftsmanship from across the world.

This mosaic-lined medieval church was built by the world's first admiral and still holds mass in ancient Greek.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

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

Tiny memorials honor individual victims of the Holocaust.

This little medieval church hidden in the center of Yerevan was lost and rediscovered—twice.

This ancient monastery complex was transformed from an island to a peninsula when the lake was partially drained.

This Armenian monastery was carved out of cliffs and named after the spear used to stab Jesus.

The most visited pilgrimage site in Armenia once held a saint in a pit for 13 years.

A geological oddity topped with a 2,000-year-old pagan temple.

Now a memorial, this factory was once used as a concentration camp for artists by the Vichy government.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This ancient theater was once the home of fierce gladiatorial battles.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

Sky ships, planes, and portraits left as unique tokens of hope and thankfulness.

This one has sailed five times as far as Sir Francis Drake's famous ship.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

Giant, friendly pelicans in Central London, the most unlikely of places.

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.