Places mariska135mm Wants to Go

A unique opportunity to stay the night in retrofitted sections of sewer pipe.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

The only example of a Paris Métro sign in use at a subway station outside of the French capital. 

At 207 feet, one of the world's longest continuous escalators.

The deepest metro station in the world.

No one knows who's responsible for decorating this tunnel with stuffed animals, but the people love it enough to protest their removal.

Stockholm's narrowest alley is barely over two feet wide.

The remains of Alfred Nobel's first nitroglycerine factory can still be found on the shores of a Swedish bay.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

Stockholm's deepest subway station is also a stunning ecological wonder.

A hidden bathhouse in one of Stockholm's oldest and busiest neighborhoods is open to anyone who can find it.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

Sweden's first nuclear reactor, R1, can be visited 25 meters underground.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

A tiny church on a man-made island in the Adriatic.

The design of the Palacio Salvo has been described as "a lighthouse on top of a building."

Come for the springs; stay for the mud bath.

The larger of two volcanic peaks rising out of the crystalline waters of the Caribbean.

A must for film lovers in Madrid and home to the Spanish Film Library's projection space.

The Catlins region has a bounty of breathtaking waterfalls, the best is arguably Koropuku Falls—a majestic waterfall with an enchanting bush walk.

Three pristine alpine lakes named in memorial of an accident that resulted in three different plane crashes.

This hidden gem along the Utah-Arizona border is truly worth the rugged journey.

This magnificent natural sandstone bridge is one of the largest in the world and is an iconic symbol for Lake Powell.

The only natural cave bath in all of Europe.