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

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

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

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

Sweden's southernmost prehistoric rock art is hidden just outside Gothenburg.

From Nazi chemicals to the CIA, this architectural marvel has played a fascinating role in German history.

One of the few surviving street funiculars in the world.

Along the Rhine, about a mile from the historic Munster, learn the heartrending story of two lovers torn asunder, cast into unknown layers of time and space.

A geothermal energy project gone wrong is fracturing the city's picturesque architecture.

A flamboyant five-story building in Bulgaria resembles a crawling snail.