Religious dwelling in a Spanish volcano.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

The oldest operating roller coaster of its kind, the Montaña Suiza has been thrilling riders since 1928.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

A moody and picturesque riverside ruin overgrown with vegetation.

A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."

This natural French spring has been turned into a magical grotto by Roman and medieval constructions.

This life-size replica of the Statue of Liberty's flame is also a tribute to Princess Diana by default.

How did a French journalist’s grave become the sexiest statue in the cemetery?

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

This 19th-century fountain's namesake animal isn't what you think it is.

Giant topiary dog once played a role in a terrorist bomb plot.

A museum dedicated to the Spanish occult in a town that was terrorized by the Inquisition.

A quarry cum sculpture park where the works of art are chiseled into the very walls.

This 5,000-year-old tomb once had its own hinged door.

A treasure trove of fine art is hiding inside this small medieval abbey in Gascony.

A bizarre sculpture garden in the south of France.

Winston Churchill painted this lake during his stay Woolsack Castle in the Landes forest.

A tiny, forgotten park of surrealist sculptures in Angouleme.

The vibrant buildings in the “capital of the comic strip” celebrate the art form that made it famous.

The largest underground church in Europe.

The bizarre home and sculpture garden of an eccentric artist.

Gargoyle head that brings good luck.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.