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

Shrapnel, dynamite, bullets and Franco couldn't destroy this bust, rescued and kept hidden as a family secret for over 40 years.

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

The lengthy skeleton of one of the tallest Spaniards of all time is on display in Madrid.

A towering monument in Spain has proven to be more labor-intensive than initially planned.

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

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

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

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

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

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

Amsterdam's Red Light District leaves little to the imagination.

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

Debatably clever, or just plain honest hotel advertised as "The Worst Hotel in the World."

This 1920s Amsterdam neighborhood was built as a giant experiment in concrete construction.

This cheese shop also houses a museum devoted to Dutch dairy.

This pirate-broadcasting-tower-turned-restaurant played a rebellious role in the history of Dutch television.

This museum inside Amsterdam's largest cemetery explores how people deal with death.

Famed for its pie, this eatery has a hidden tunnel that allowed Catholics to secretly walk to church during the Reformation.

A rare tour of an aristocrat's private home reveals valuable 17th-century paintings from artists like Rembrandt.

This bird-loving brewery is situated in an old municipal bathhouse, nestled beside a 300-year-old windmill.

An overgrown and largely forgotten cemetery lies hidden within the outskirts of Amsterdam.

The world's oldest Jewish library was founded by Sephardic Jews in 17th century Amsterdam.

This basement museum explores the art and artistry of fascism.