A spectacular walk on the flank of a gorge.

A New York–based physician returned home to Spain to build his own elaborate monument to Christopher Columbus.

The walls of these four caverns are filled with art that dates back to the earliest human presence in Europe.

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

A well-restored ancient archaeology site gives a real feel for life during the Roman age.

The Roman city was the birthplace of various emperors and is home to one of the empire's most impressive architectural feats.

This surreal-looking tree pruned more than 1,000 years ago is still producing olives for oil.

Stormy conditions send jets of seawater bursting through holes in the cliffs.

This imposing modern citadel started out as a home renovation project.

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

This abandoned, turn-of-the-century astronomy hub is now the subject of more photographs than it ever took.

The largest prehistoric cemetery on the Balearic Islands dates back over 2,500 years.

The ruins of a 2,000-year-old Roman fishing village perched on one of the best beaches in Spain.

Remarkably intact Roman stone fortifications have encircled this Spanish city for centuries.

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

Spain's stunning solar energy plant.

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

The unexpectedly beloved remnants of a controversial thermal power plant.

A celebration of solstice followed by a fiery purging of evils.

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

A breathtaking and biodiverse wilderness in the mountain setting of Ernest Hemingway's "For Whom the Bell Tolls."

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

Stuck in the middle of a modern Madrid city block are the remains of a 19th century sports complex.

You can soak in three relaxing pools filled daily by the tide.