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

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

The portrait of a man from Japan who sent weekly letters to a Dutch hotel he never visited.

In the Netherlands, one of the world's largest private car collections can be found.

Mosaics created from 11 million cigar bands.

This still-celebrated home was a radical architectural experiment in 3D De Stijl.

Amsterdam's former hotspot for public executions and dissections.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

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

Long tunnels run under the ancient chariot racing circuit to the tower.

Where the lovelorn find a home for their sentimental keepsakes.

Cliffside houses provide a spectacular view from their perch above the valley.

Vibrant street art created with mixed media.

Week-long block party becomes a competition for the best decorated street.

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

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

A daily pyrotechnic celebration marks a beloved tradition during Valencia's festival season.

This cavern was used as a hidden hospital and safe house during the Vietnam War.

Artifacts and memories from the Vietnam war, located in a place that experienced it first hand.

A musical instrument played by the sea.

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

The very first subway station in New York City is beautiful, decked out in chandeliers, and ... abandoned?