A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Apartment complexes built into huge repurposed natural gas tanks.

Dine amidst exotic plants at this former royal greenhouse.

From Ancient Rome to WWII, Neupfarrplatz has over 2,000 years of history underneath its main square.

When a medieval fire claimed the original St. Stephen’s Cathedral, it sparked a pattern of unquenchable organ building.

Walk inside a half mile long crevice right outside the town of Garmisch Partenkirchen.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

Go surfing on this urban wave, "hacked" by local surfers.

A quaint Russian village in the middle of a German metropolis.

A restaurant and observation deck built in a unique broadcasting antenna.

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

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

2300-year-old Roman road connecting the empire.

Try not to get slimed in Tribeca.

A Victorian-era British railway viaduct has been transformed into an elevated garden.

Over 70 independent businesses have set up shop in this former Victorian department store.

Be on the lookout for the symbolic insect all over the city.

19th century museum with an eclectic mix of curiosities, from Egyptian artifacts to items on archery history to the skull of the world's oldest horse.

A towering steel-and-bronze figure whose playful nickname outshines its official message of hope