The construction of a tram line unveiled hidden remnants of the old medieval city.

Artist's eccentric property excessively decorated with found objects and work of his own.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This massive blockhead sculpture hides an entire library.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

A floating cat sanctuary on an Amsterdam canal.

A curious collection dedicated to human and animal anatomy and pathology.

Museum preserving torture methods from the past.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

The most visited, and possibly most controversial, museum in Germany.

A narrow ghost town built onto a peninsula behind a Colombian Slum.

Colorful lights and mirror-like brine pools create trippy illusions within the historic mine.

Hidden amid the tropical forest in the Caribbean Sea are the decaying ruins of the Cocaine King's luxurious island party home.

Former drug lord’s manor, now a theme park. Watch out for the hippos.

Unparalleled stargazing, one of Colombia's best observatories, and a swimming pool can all be found in the middle of this ancient tropical forest.

The caldera of this mini-volcano has been turned into a naturally heated mud bath.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

A vintage video game wonderland in downtown Reykjavik.