A mailbox that saved a nature reserve.

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

The permanent home of Elektro, the celebrity automaton of the 1939 World's Fair.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

Nine of the very few concrete ships ever made in the U.S. are beautifully decaying off a Virginia pier.

This abandoned nuclear cooling tower casts a shadow over a bucolic town.

Ethereal alien hums and haunting whale songs emitting from...a giant sheet of vibrating metal?

An unknown Hall of Fame in Jackson, Tennessee.

The site of the one of the most deadly train wrecks in American history.

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

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

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

Home to drunken tower-climbing goats... seriously.

This replica of the Greek structure is in the heart of Nashville.

Visit this playground of waterfalls, caves and sinkholes.

More than five miles of underground passageways.

All that's left of the quintessential "cabin in the woods."

Enormous lake at the bottom of a unique cave system.

Home of an evil witch famous within southern folklore.

An equine tribute in a charming Southern city that calls itself "The Horse Capital of the World."

Kentucky's longest operating jail is now a spooky spot to spend the night.

The oldest operating Mississippi River–style steamboat still navigates the Ohio River.

The history of whiskey and all of its boozy glory, from Colonial days to modern American cocktail culture.

Outstanding collection of 19th century medical instruments includes a life-size figure cast from as many as 200 cadavers.