The elaborate clockwork contraptions in this Scottish gallery create small worlds of whimsy and horror.

The world's oldest surviving music hall was also once a freakshow.

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

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

A once-magnificent collegiate church is falling into ruin.

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

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

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

This Belgian palace was long the domain of priests and aristocrats but is now being turned into an art commune.

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

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

A wonderfully kitsch bookstore the size of a supermarket.

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

A magical and peaceful ruined Cistercian abbey in what is now southern Belgium.

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

The tiny Belgian town's ancient version of Mardi Gras involves eerie wax masks, sticks for warding off evil, and ostrich plume hats.

One of the deepest indoor swimming pools in the world.

Only museum in the world devoted to bookbinding and book arts holds a permanent collection representing five centuries.

Built by crowdsourcing, this wooden foot bridge saved a part of Rotterdam that was languishing in wait of city funding.

This imposing tower named after the mythical sword of King Arthur is considered the tallest freestanding climbing wall in the world.

Lombardy poplars planted to imitate the size and shape of the Cathedral of Notre-Dame de Reims.

The works of poetry's biggest names grace the walls of the city of Leiden, all carefully painted by hand.

Home to the world's oldest functioning orrery.