This small museum tucked within a subway station holds pieces from Madrid's past.

A subterranean relic of the Spanish Civil War hides below this picturesque park.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

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

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

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Local arts organization founded in a former church.

Artist James Turrell's ode to dawn and dusk on the campus of Rice University.

This historical air terminal in Houston is slowly becoming an aviation museum dedicated to the city's aeronautical history.

The peaceful space is adorned by paintings by the famed abstract artist Mark Rothko.

At the "Garage Mahal" in Houston, car culture is about more than just driving.

Fantastic collection celebrating the final send-off.

A 90-year-old underground water reservoir offers a more industrial kind of tranquility.

Salaguti's live-in museum: a fortress against criticism and consumer art.

During an annual Catholic feast in this tiny Spanish village, men dressed as devils leap over rows of babies to cleanse them of sin.

This Gothic church houses ornate royal tombs and a magnificent gilded altarpiece.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

On the wall of this medieval walkway, a symbol of the Spanish Inquisition.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.

One of Europe's largest supercomputers is housed inside of a disused chapel.