Europe's second largest ossuary wasn't discovered until 2001.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

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

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

A little sculpture with a large wardrobe.

Theme park featuring miniature replicas of European monuments.

Climb inside an iron crystal magnified 165 billion times its normal size.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

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

This lucky bronze frog was gifted to Madrid by a casino.

A lush indoor jungle fills this bustling Madrid transportation hub.

This historic electric train has operated with regularity since the early 1900s.

A contemporary art installation housed within a Gothic cathedral.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

The world's largest wooden structure.

One of the two original gateways into the Kasbah, this gateway is a nesting site for storks.

The largest madrasa in Morocco once housed more than 900 students within its exquisite walls.

A fortified city, home to a remaining population of five families

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.