A mocking tribute to the past and modern leadership of Prague.

Macabre astrological automaton clock dating to the late 1400s.

An ornate private entrance to the Vienna subway built specifically for the emperor.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

A silly medieval mural preserved on the side of a Viennese house.

The topiary maze at the Habsburg hunting lodge.

A tilted half-timbered house from 1672 is built into a salvaged segment of a medieval wall.

The small alleys in Lübeck's Old Town are a result of medieval urban sprawl.

The bells remain in a shattered heap exactly as they fell when the church was bombed in World War II.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Remnants of an exploded schooner and wrecked submarines form a breakwater.

The entrance to this Frankfurt subway station looks like an old tram car crashed into the concrete sidewalk.

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

The fairy tale castle of the "fairy-tale king."

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

The 1852 novel "Uncle Tom's Cabin" lends its name to a subway station, a street, and several shops on the edge of Berlin.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

Metro station with a claim to rock n' roll fame.

Named after a militant urban guerilla, this famous former squat is a graffiti-covered stronghold of leftist culture.

Berlin's old airport.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.