These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

The largest treasure hoard in Europe is contained in a castle that was bombed out during World War II.

The world's largest man-made underground caverns offer unparalleled underwater wonders.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

Tiny castle in the middle of the Rhine made you pay to pass.

A fiery crater has been burning in the Karakum Desert since 1971.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

A museum dedicated to the Spanish occult in a town that was terrorized by the Inquisition.

A submerged archeological park still holds the wonders of a Roman Sodom.

A set of ancient drawings in the desert of Peru that are so massive, many of them can only be fully seen from the sky.

Ain't no party like a ghost town party.

The mortal remains of an estimated 70,000 people lie in the basement of a monastery in Lima, Peru.

Now containing the bones of the actual conquistador, instead of someone else.

Nazca pilgrimage site covering 370 acres is a popular stop for archeologists and looters.

A mysterious pre-Incan ruin believed to have miraculous healing powers.

Besieged by war, this castle ruin has crumbled into a peaceful picnic spot.

A preserved dragon's rib that remembers the legend of the founding of the city of Atessa.

Art and armour fill every inch of this rich kid's Italian villa.

Ruins of a German Castle on top of a towering stone pillar.

The industrial monstrosity known as Bagger 258 is a colossal mining machine built in the DDR - but now left for dead in a German field.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

Pompeii's less famous neighbor is still revealing her secrets.