A neighborhood park in the city of Cáceres hides what some believe are revolutionary examples of Neanderthal cave art.

An abandoned mine now resembles a post-apocalyptic landscape of derelict buildings and blood-red pools of water.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

The hidden ruins of an old hydroelectric plant reclaimed by nature.

A micro-communist utopia in Spain with no police, no mortgages and full employment.

Moorish signal station on a stratgic rocky outcrop.

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

The cathedral of a controversial, conservative, schismatic sect that declared the Catholic Church heretical and founded its own succession of popes.

The verdant mossy ruins of a Franciscan monastery lie in the remote Sintra hills awaiting exploration.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Ring the bell to enter a bar that looks equal parts museum and old curiosity shop.

This once-forgotten oasis in the middle of Lisbon was first created over a century ago quite by accident.

This semi-secret storybook hedge maze is also the oldest garden in the city.

The former 1920s mansion of a prominent Catalan developer was used as the Soviet Embassy during the Spanish Civil War, and there is still a bunker below the garden.

This mansion oasis contains gardens, sculptures, and fountains just off the busy Plaça Kennedy in Sant Gervasi.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

A toxic ghost town sitting atop a massive coal fire.

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

An abandoned stretch of highway, deteriorating next to the operational one.