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

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

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

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

The bronzed skull of a beheaded traitor was affixed to the city gate in the 17th century.

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

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

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

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

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

Christ's blood preserved in a Belgian town.

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

This abandoned Belgian fortress is purposefully being left to nature.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

Climb inside an iron crystal magnified 165 billion times its normal size.

Lavish royal estate punctuated with heated greenhouses.

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

The Devil’s own choice when he needs a drink in Brussels.

Hiding the longest subterranean river known in the world.