An artsy hidden staircase leads to breathtaking views of San Francisco.

A terrific purveyor of natural history objects and curios.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

A huge musical instrument played by the ocean.

A monument to the more than one million enslaved Africans deported from the port of Ouidah.

Africa's Venice on stilts.

This wrecked ghost ship has been rusting on a Greek beach since the 1980s.

A schooner, nicknamed "The Unsinkable," with a long history of survival in the Indian Ocean.

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

An abandoned boat that's been stranded mysteriously for decades.

This massive monument towers over the city as a constant reminder of the lives lost during Algeria's hard-won war for independence.

This former cathedral is now a bustling library packed with students and pigeons.

A century-old stone hermitage overlooks this remote pass in the Hoggar mountains, surrounded by a landscape of eroded volcanic cores.

Classical ruins that remember ancient Rome's presence in Africa.

The abstract sandstone rock formations at this Algerian national park are rich with prehistoric art.

This dizzying span over the ancient Algerian city was once the highest suspension bridge in the world.

An extraordinary mix of Phoenician, Roman, early Christian, and Byzantine ruins beautifully set overlooking the Mediterranean.

The original resting place of Queen Cleopatra and Mark Antony's only daughter.

Two hula hoops appeared on the tree after a storm, and the collection kept growing.

Grant Wood painted some of his most famous works of art at this studio.

The only museum in the world dedicated to the history of sprint car racing, next to one of the country's most historic dirt tracks.

The headquarters of the prestigious World Food Prize celebrates the heroes in the fight against hunger, has no cafeteria.

This massive railroad spike celebrates the 1939 premiere of the movie “Union Pacific.”

An obelisk commemorating Lincoln's role in connecting the coasts.