A lush indoor jungle fills this bustling Madrid transportation hub.

A heated statue pays tribute to one of Sweden's great actresses.

The discovery of an old wall led to the creation of this fascinating museum about the city in the Middle Ages.

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

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

This gem from the industrial age helps visitors and residents alike traverse hilly Stockholm.

A magnificent, long-abandoned castle built in the wake of the reconquest of Spain.

This species of wild goat stars in witchy legends and frolics among the park's eerie rock formations.

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

Some 2,000 carvings show this rare desert spring has been an oasis for travelers for over a thousand years.

This Dakar museum exhibits artworks and artifacts honoring the daily lives of Senegalese women.

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

Deliberately hidden for centuries, the magnificent Saadian Tombs were eventually uncovered in 1917.

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

Stockholm's deepest subway station is also a stunning ecological wonder.

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

The Swedish flag over this small naval fort signals that the nation is at peace.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

Five million people are laid to rest here, more than the population of Madrid itself.

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

A little-known cafe in an old copper bridge tower with 360-degree views of the harbor.

The ornate miniature mansions were built for Istanbul's feathered residents.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Bacteria and algae give the salty water its bubblegum hue.