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

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

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This easily overlooked memorial immortalizes the scars from the 1956 Hungarian Revolution.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

A garden in Lisbon filled with giant porcelain creatures.

Ring the bell to enter a bar that looks equal parts museum and old curiosity shop.

This charming candle shop has been in business since 1789.

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

The world's oldest bookshop still in operation.

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

A small museum displays some of the artifacts discovered during a subway station renovation.

Infamous and now demolished panopticon prison built by its former inhabitants.

Built to power trains, the engines in this building provided the entire city of Madrid with electricity during the Spanish Civil War.

This 18th-century project to build the world's tallest gravity dam was never completed.

These abandoned country fairgrounds are filled with replicas of Spanish monuments.

Strange masks and obscure costumes are housed in this old Madrid corrala.

The remains of this misplaced church were moved here stone by stone.

An old, deep well, connected with a miraculous, divine rescue and the patron saint of Madrid.

A pair of gigantic baby heads greet passengers at Atocha Station.

An automaton perched above an classic clock and watch store

An iconic photograph from the Spanish Civil War saved this shrapnel-scarred historic house from destruction.

Guitarist Paco de Lucía overlooks travelers as they pass through this train station dedicated to his legacy.