A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

Europe's largest natural bridge has a 19th century royal chateau built into its side.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

An industrial relic is now one of Europe's most staggering art spaces.

This temple to the sturm and drang of Richard Wagner contains a dragon's cave and reptile zoo full of living "dragons."

This German bone house contains the remains of some 20,000 souls.

An elevator into the Baltic Sea.

An enormous warehouse filled with parade floats collected from over 50 years of patriotic celebrations.

The resting place of a Civil War celebrity's amputated limb.

The site of the climactic scene from the classic horror film is now a historic landmark.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A blank headstone topped with a pile of pennies marks the final resting place of the infamous assassin.

An ancient monastery, a locked room, and a mysterious book heist.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

Silent memorial, using bone conduction to take people back to the Dresden Bombing of 1945.

This East German military command bunker was ready for World War III.

Enter the cabin of a life-sized Hindenburg replica.

This Nazi-built amphitheater was constructed on a sacred mountain site used by various German cults.

The naturally mummified body of a peasant girl saint.

The Suurhusen church tower in Germany leans over farther than the famous Leaning Tower of Pisa.

This unusually shaped mountaintop tower looks like a UFO floating over the city.

Two stunning 17th-century libraries and a cabinet of curiosities.

No need to strap in for a "ride" on this walkable roller coaster.