A fifth-century temple improbably built into the side of a cliff.

A part of the world's largest marsh seems to be growing bright red Martian grass.

A canvas of crops grow from vibrant red soil in this terraced farmland.

This century-old cinema house has a marquee that has been hand painted by a single man for over 25 years.

The celebrated eyesore created by starry-eyed sweethearts.

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

A subterranean shelter remains intact under a busy Paris railway station.

A haunting collection of the vanished and disappearing natural world.

Paris' linguistic guide to the international language of, yes, love.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

Abandoned railway line circling the city of Paris.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Notorious artist squat renovated into legal studios.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Colorful and chaotic stacked hotel in North Holland.

The world's only museum devoted to the wonders of fluorescence.

Cat art as far as the eye can see.

Museum preserving torture methods from the past.

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

The Belgian library displays burned books that were salvaged from the fires of both world wars.

Theme park featuring miniature replicas of European monuments.

Cozy basement bar sports an inventory of over 2,000 beers.

Lavish royal estate punctuated with heated greenhouses.