A unique seaside cave where Aleister Crowley faked his own death.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

Eat the ultimate iteration of Portugal's most beloved pastry.

Sip cherry liqueur at a bar dating back to 1840.

One man's remarkable private collection of art from around the world.

Hidden beneath a beautiful overlook you’ll find the history of the city depicted in comic strip format next to a pay toilet.

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

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

The world's oldest bookshop still in operation.

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

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

The Netherlands' first car tunnel has an unusually rectangular shape.

A stairway to heaven, or to nowhere at all.

One of the most easily accessible examples of the rare 1960s UFO houses.

A subterranean display of public art and architecture.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A beautifully eclectic mix of architectural styles.

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

An ancient Egyptian temple in the middle of Madrid, Spain.

A strange rock formation with numerous legends trying to explain it.

The attic of a four-century-old canal house hides a clandestine church.

A condensed piece of China floating in a Dutch harbor.

A modern reimagining of a medieval city gate.

The world's first floating farm is staffed by one human, three robots, and 35 cows.