An open-air sewer system that was covered piece-by-piece over 300 years.

The patron of this extravagant Art Nouveau confection insisted that nothing less than a boat should project from its facade.

A wonderfully kitsch bookstore the size of a supermarket.

An undulating wicker beast looms peacefully atop a sand dune in Belgium.

The Belgian royal family's private depot now stands abandoned and forgotten alongside the tracks.

This bike path was sunk below water level for maximum wonder.

Descend into the tunnels to experience the life of a coal miner.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

Because sometimes you need to make a batch of frites even when the stores are all closed.

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

This recently restored crypt was once plagued by liquefying coffins and exploding caskets.

A fantastical bed and breakfast with magically unique rooms.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

When you're a great Russian Tsar, even your vomit gets a statue.

This Greek temple, open only an hour a day, was the site of a war of tastes between an architect and an artist.

A Museum of Psychiatry in a still-operating mental institution.

In an area where the remnants of WWI are discovered on a regular basis this preserved frontline trench may be the most amazing.

A fantastical 13th-century fortification sandwiched by a modern hotel in central Brussels.

Artwork tucked within the trees greets visitors with surreal sonic experiences.

This modern arts center is built around a gem of late-Baroque architecture.

One of the deepest indoor swimming pools in the world.

A rare example of World War I trenches from the British front.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.