Remnants of the Nazis' occupation of Denmark linger along the sand.

Dedicated to the history and culture of smoking, this small museum now includes a vape lounge.

The floorboard scrawling of a tragic madman is on public display outside a Paris hospital, much to the dismay of its opponents.

An off-the-beaten-path boutique stuffed with an eclectic collection of upcycled goods.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

A haunting collection of the vanished and disappearing natural world.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

Paris' linguistic guide to the international language of, yes, love.

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

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

Notorious artist squat renovated into legal studios.

France's most famous cemetery, with some of its most curious tombs.

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

This Denmark theme park is part family attraction, part experimental archaeology project.

The oldest amusement park in the world has been providing a nice spot to have some fun since the 1500s.

A little-known cafe in an old copper bridge tower with 360-degree views of the harbor.

Nearly 40 miles and 1,000 years of limestone mines under Denmark.

The world's largest maze is a nature park with nearly 200 decision points.

The gilded, masterful astronomical clock will calculate time, dates, and planetary positions for thousands of years to come.

This secret collection of the strange and occult was rediscovered in a forgotten room of an old house.