A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

This bazaar is one of the oldest in the Arabian world.

This spectacular mosque houses the second-largest chandelier in the world.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

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

This church on a Tohono O'Odham reservation has stood since 1797.

Sleep where gangsters fell amidst smoke and flame, with nary a bullethole to show for the legendary struggle.

One of the oldest Mexican restaurants in the United States air-dries its trademark beef in a dangling outdoor cage.

A natural history wunderkammer in the middle of the desert.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

This noble mash-up in eastern Luxembourg is part Medieval, part Renaissance, all castle.

There has been an astronomical clock on this spot since the 14th century.

A copy of the Statue of Liberty greets visitors to the birthplace of Auguste Bartholdi.

A Looff creation in Santa Monica best described as “a California-Byzantine-Moorish-style fantasy.”

One of the first skyscrapers in Santa Monica, and a famous getaway for the Hollywood elite of then and now.

A second generation sun-powered marvel lights up the night.

A treasure hunter's tiny bar, harboring celebrities since 1959.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.