An ancient Viking runestone hidden in plain view in Stockholm's old town.

Sweden's "good old days" painstakingly re-created in a model village.

The world's largest model of our planetary system.

It houses the remains of a 17th-century version of the Titanic.

A long-buried ancient ruin unearthed right in the middle of the city.

Southern Italy's spinning top village.

This religious complex carved into a cliff is steeped in legends of miraculous stags and the Holy Grail.

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

These three pillboxes still remain as a witness of the Spanish Civil War in a park of Madrid.

This fascinating and poignant museum chronicles every imaginable aspect of Spanish colonialism in the Americas.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

Stuck in the middle of a modern Madrid city block are the remains of a 19th century sports complex.

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

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

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

A lush indoor jungle fills this bustling Madrid transportation hub.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

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

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

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

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