A set of medieval stained-glass windows tell the gruesome story of a Viking siege.

One of England's most famous churches hides a pair of little known architectural treasures.

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

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

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

It took 40 years to build this Eden-like garden in Marrakech, later restored by Yves Saint-Laurent.

This underwater graveyard commemorates a group of murdered 16th-century missionaries.

This local emblem is the oldest and largest dragon tree in the Canary Islands.

According to the Guanches, the aboriginal people of the Canary Islands, the king of evil lives inside this volcano.

A completely underwater art museum sends a stark message about humans' impact on the environment.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

The chefs at El Diablo use heat generated by an active volcano to cook the food.

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

A science fiction-inspired apartment building designed by a famous Spanish architect.

An architect transformed this abandoned cement factory into his castle-like workshop.

Mountain where Jesus was first tempted by the Devil.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

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

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

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.