Oldest Museum of the Netherlands is a true cabinet of curiosities.

Head underground and take a tour of the city's working sewer system, and see the underground river Senne, which defined Brussels for centuries before being covered in the 19th century.

Potato-peeling mannequins, Inca art, and a dangling tuber mobile help trace the history of fries at this Belgian museum.

A visionary precursor to the Internet made of index cards.

This sprawling Belgian fort was once thought of as impenetrable but now it is simply an abandoned relic.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

Physicist’s epitaph provides final confirmation to a career of turmoil.

A neo-Gothic mansion now houses a wunderkammer of analog tech that hits on all the senses.

Museum devoted to the artificial language of Esperanto.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

A spherical "micro-nation" in the heart of Vienna.

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

One of the world’s smallest bars, just 13 square feet, is brimming with speakeasy flair.