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

Built on a medieval synagogue, this church has a burial crypt, tunnel system, and Jewish ritual bath hiding deep underneath.

According to Greek mythology, this natural spring is the home of a freshwater nymph.

Italian cave with exceptional acoustics and an unsavory history.

At more than 5,000 years old, these structures are among the oldest free-standing stone buildings in the world.

Abandoned Roman Catholic chapel abused by Satanists before being restored.

Ancient mysterious ruts carved in the bedrock.

This unique building in the main square stands out among the city's typically Baroque architecture.

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

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

The fishing boats that moor in this small lagoon enter and leave through a tunnel to the sea.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

This grand Georgian manor house was converted to serve as an isolation hospital before it was abandoned and destroyed.

Hundreds of enormous icebergs drift through this waterway every year.

An ancient Viking village in North America that predates Columbus by 500 years.

In the Hugging Tree Forest, lingonberry marshmallows, hot chocolates, and the best campfire lattes north of the Arctic Circle come to you.

A chaotic collection of maritime artifacts, art, and really whatever else happens to be around.

This rocky spread has been squeezed up directly from the bowels of the earth.

This oddly named town refuses to change its phallic moniker.

The tiny airport in remote Newfoundland that inspired a hit musical is also a modernist architectural gem.

A memorial to a giant seabird that was hunted to extinction.