To enter this cluttered-yet-cozy sanctum of Belgian brews, ring the bell and tell the gatekeepers you've come “to taste beer.”

An open-air sewer system that was covered piece-by-piece over 300 years.

The site where one of the most famous poems of World War I was composed is preserved to honor the legacy of the work.

Descend into the tunnels to experience the life of a coal miner.

Somewhere there is a giant who can no longer poop, but now travelers can stay inside his anus.

The "stairway to heaven" lookout tower was built to resist weather, arson, and the laws of physics.

This bike path traverses the treetops.

The Belgian royal family's private depot now stands abandoned and forgotten alongside the tracks.

This small corner bar is home to a rare 1930s dance organ that still plays tunes for one Euro.

The bronzed skull of a beheaded traitor was affixed to the city gate in the 17th century.

This bike path was sunk below water level for maximum wonder.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

Hiding the longest subterranean river known in the world.

This ghost town in Belgium will lose its street art when it ceases to exist.

At this 16th-century monastery in rural Bulgaria, visitors can also spend the night.

Founded in the 4th-century, the town of Pernik plays host to the Surva Carnival⁠—a magnificent display of masked Kukeri dancers.

A gigantic statue of a Russian soldier watches over the ancient city of Plovdiv, a prominent reminder of the Soviet period in Bulgaria.

The remarkably well-preserved final resting place of a powerful ancient Thracian king.

This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

Abandoned railway line circling the city of Paris.