A desert ghost town—occupied for only 12 years—was once home to more than 500 silver mines.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

Cold war icon and onetime "hole" in the iron curtain.

This sandstone mansion was the home of two of Oregon's most important pioneers.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

The set location for a 1987 cult classic draws international film buffs to the middle of the Mojave Desert.

A crumbling hospital from the 1850s on Roosevelt Island.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

Hollywood's oldest hotel is the site of the first Academy Awards, the birthplace of Marilyn Monroe's career, and the home of Montgomery Clift's ghost.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

Standing atop 2nd-century Roman ruins, this church is one of the oldest and most iconic in Old Cairo.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

This giant subway sculpture celebrates the fruit that inspired the theory of gravity.

No one knows who's responsible for decorating this tunnel with stuffed animals, but the people love it enough to protest their removal.

Stockholm's deepest subway station is also a stunning ecological wonder.

It houses the remains of a 17th-century version of the Titanic.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

A monument to Malchik, a stray dog who lived in a Moscow metro station until his tragic death.

Gargantuan home of Russian science.

Moscow's imposing monument to the Space Age.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Immortal combat in a Moscow museum.