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

A historic Christian shrine nestled within a spectacular natural cave.

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

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

This ancient amphitheater was restored in the early 1990s.

This magnificent castle grew from a small Moorish fortress, and reportedly inspired two iconic Disney castles.

An accidental trick of light casts the perfect shadow of a pilgrim of the Camino de Santiago against the cathedral wall.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

The world's largest grapevine has produced a delicious harvest at Hampton Court Palace for almost 250 years.

This Roman arena once played host to bloody gladiatorial battles.

The cave where Saint Genadio meditated and played chess.

This beautiful spit of land was once the summer playground of the king of Spain.

The ruins of the Sacred Heart Memorial, which was first “shot” by a weird firing squad and then dynamited during the Spanish Civil War

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

An ancient Roman temple first dedicated to an emperor's wife is now a church.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

This curious, round temple is the oldest still-standing marble building in Rome.

This former power station is now a museum dedicated to the region's coal-producing history.

Legends surround this natural rock formation that looks like a Moorish king wearing a crown.

Devastated landscape used for hundreds of years by the Romans as their primary mining site.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

These "mermaids" that surround a plaza in Segovia are rather sphinx-like.

The fragmented remains of a massive public bath connected to the city's water supply.

A stunning gilt bronze relief denounced by Hitler as "degenerate art"—even though it was dedicated to the Nazi leader.