This 1st-century CE Roman bath sits under a carpark.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Half-drowned wooden stumps and stone blocks are all that remain of a Victorian landing that was destroyed by storms.

Regency-era excess on the English Coast.

The rotting skeleton of a shoreside fun fair that was destroyed by fire and storms still haunts the Brighton ocean view.

Decrepit Victorian public lift is a white-knuckle ride.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Archduke Ferdinand II's collection of rare objects is considered one of the oldest museums in the world.

Devilish masks, handicrafts, and pieces of old buildings create a snapshot of life in a historic Alpine region.

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

The oldest stone house in Paris was built by its most famous alchemist.

This massive library holds what was once the largest book collection in the world.

Notorious artist squat renovated into legal studios.

France's most famous cemetery, with some of its most curious tombs.

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

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

Commonly acknowledged as the only public monument to the Devil himself.

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