Abandoned Roman Catholic chapel abused by Satanists before being restored.

These temples are among the oldest free-standing stone buildings in the world.

This 50-foot-deep sinkhole created in the 14th century is home to rare plants and fungi.

A centuries-old forgotten underworld lies beneath Malta.

This Stone Age solar temple aligns with the sun on each equinox and solstice.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

This camera store in Milan holds one of Europe’s largest collections of luxury-antique cameras.

This poignant art installation raises awareness of violence against women.

A diminutive statue that was inspired by the sculptor's own daughter.

A triumphant marble and bronze fountain depicting a 15th-century Hungarian king and his hunting party.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

Budapest's Communist-era statues, banished to the suburbs.

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

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

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

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

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

In the summer, the area around this sculpture transforms into a vibrant concert venue.

Atop this library is one of the most beautiful green spaces in Warsaw.

This bell stars in a tragic love tale and is said to make wishes come true.

A statue honors the children who fought Nazis in Poland.