This now-deactivated naval base defended the Florida coast for centuries.

A former hospital is now home to a pizza parlor and maybe a few ghosts.

Pensacola's UFO home has withstood many hurricanes—just as the experimental 1960s design intended.

An abandoned, rusty old relic of railroad history stands at attention over the Cuyahoga River.

The plants form a living library and laboratory for researchers and students at Michigan State University.

What was once the largest NFL stadium.

Once the extravagant escape of the Ford family, this enigmatic ruin now stands as a haunting reminder of its former glory.

This monument commemorates the only American soldiers to have directly fought Russians during World War I.

Visit this playground of waterfalls, caves and sinkholes.

In one of America’s oldest mountain ranges, a long-awaited section of a scenic highway is now open to the public.

A museum to a cave explorer whose tragic death was a media sensation, and whose corpse became a tourist attraction.

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

You can climb to the summit of Black Mountain, as long as you sign the waiver.

A sprawling outdoor museum filled with larger-than-life works of art.

A natural gas leak provides a flickering flame beneath a waterfall.

One of the last Jazz Age "Wonder Theaters" in New York City.

This former Norwegian sailor's church is slowly being taken over by ramshackle robot musicians.

Tucked in a nondescript downtown Brooklyn mall is a bar containing a remarkable turn of the century anatomical wax collection last seen in 1920s Berlin.

The oldest surviving synagogue in New York City is now a soaring art space.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

Nondescript elevator doors open to reveal a stunning, surreal world.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.