This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

This fantastical waterfall is hidden in a cave located in a cracked cliff.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

This massive library holds what was once the largest book collection in the world.

Ruins of a German Castle on top of a towering stone pillar.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

This South London cemetery holds the remains of more than 15,000 people.

A hospital closed seemingly in the middle of operations, leaving behind fodder for horror films and ghost hunters.

Northern Ireland's Brobdingnagian stepping stones.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

There is no trying to fall in love with this Star Wars fountain, you just do or do not.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

A swing to dangle you off the very edge.

A massive underwater sinkhole made famous by Jacques Cousteau.

A fiery crater has been burning in the Karakum Desert since 1971.

Stroll through a wonderland of stupendous moss-covered trees.

Cabaret where the show girls are all androids, and the patrons couldn't be more pleased.

The atmospheric road was never meant to be so creepy.

Fine dining in the bizarre world of Lewis Carroll.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

Eighteen miniature death-scene dioramas.

Rising from the sea like a stone monster.