A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

One of the greatest maze designer’s greatest mazes.

This museum houses an imposing skeleton army comprised of creatures great and small.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

A haunting collection of the vanished and disappearing natural world.

A museum of carnival attractions where you are invited to ride the rides.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Abandoned railway line circling the city of Paris.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Plans for this local observation tower were debated for so long, the allocated funds lost value and the design had to be changed.

An artist has turned what most people would consider a bathroom nightmare into a work of political art.

An abandoned lighthouse awaits its destiny: being buried under shifting sand.

This ultra-modern wooden boardwalk turns the ocean into a swimming pool.

Four alabaster giants contemplate the tides on the shore of Denmark.

The northernmost point in Denmark is a turbulent sandbar created by two clashing seas.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

Vortex-shaped aquarium hosts Europe's largest school of piranhas and other ocean creatures.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

Copenhagen's celebrated theme park and gardens.

This annual Belgian water race attracts bathtub captains from all over the world.

What was once a bustling mining installation is now a bustling hub of contemporary art.

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