An early Portuguese serial killer's head is alarmingly well preserved in a jar at the University of Lisbon.

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

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

The world's oldest bookshop still in operation.

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

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

This small chapel is built of human bones and decorated with a golden skeleton.

This gaping hole in the middle of a remote mountain lake looks like a portal to another dimension.

Houses are tucked between, on, and underneath giant boulders.

An abandoned socialist utopia built in the late 19th century.

An impressive home made of stone, carved more than a century ago.

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

A charming Spanish village sits atop this natural limestone overpass.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

Cursed swimming pool left abandoned is now a favorite of filmmakers and ghost hunters.

A whimsical garden of outsider art in the Spanish countryside.

The streets of a sleepy Spanish town proudly exhibit some of the world's finest graffiti.

An iconic and controversial ancient Iberian funerary urn with a hauntingly penetrating gaze.

This enchanting hamlet carved into the rock looks like something straight out of Tolkien's Rivendell.

A celebration of solstice followed by a fiery purging of evils.

Mysterious face-like images that appeared within an Andalusian house are surrounded by legends of the paranormal.

A series of recreated fortifications mark George Orwell's path through the Spanish Civil War.

This small and often-overlooked museum holds some of Spain's finest artistic treasures.

Part of the medieval watchtower is displayed in an otherwise ordinary parking garage.