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

The abandoned remains of this once-thriving hotel looms over the city, awaiting an uncertain future.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

Where condemned pirates met their grisly end at the gallows on the River Thames.

Situated on a sacred Inca site, this 16th-century cathedral took nearly 100 years to build.

A gigantic, symbolic artwork covers the side of the building.

The world's largest outdoor organ is played weekly by one of just two civic organists in the U.S.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

A former hardware store near Yerba Buena is the official home of California's history.

One of the oldest of its kind.

This elaborate towering structure was once famed for its revolutionary height.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

The oldest experimental corn field in America is still creating better ways to grow crops.

Hide from the tourist hordes in these relatively unknown, and unguarded lava caves.

Watch the newest land on the planet form before your eyes.

Paris' linguistic guide to the international language of, yes, love.

Cambria's most unique B&B features creative surroundings and fantastic food.

Pasadena glamour turned government issue.

Where the rich wintered in Pasadena.

Apartment building was once posh playground to the Hollywood elite.

This 19th-century church is now a popular roller rink.

One time home to turn of the century explosives, now hidden under the Bay Bridge.

These WWII-era murals were initially booed as a libelous portrayal of the American dream but have survived multiple attempts to have them destroyed.

The first AIDS memorial chapel in San Francisco and one of only a few in the U.S.