A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

A DIY art gallery/music venue/lecture hall dedicated to video game culture.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

An astounding collection of medical specimens, including bits of President Lincoln.

The romance of early commercial flight still fills this Art Deco destination.

An eccentric company offers eccentric millionaires the opportunity to have spaceflight-related experiences.

Headquarters of the legendary clairvoyant's readings, spiritual hospital, and massage school.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

Under a playground is a little-known sealed train tunnel that likely contains the bodies of workers trapped by cave-ins.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

An out-of-place Air Force radar dome is all that denotes this park as a former missile launch site.

This former Texas landfill is flush with 300 million-year-old fossils, all fit for the taking.

A health museum containing a 27’’½-foot intestine.

Where pardoned turkeys once spent their all-too-brief final days.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

The only place for a truly presidential dram.

Hear, smell, see, taste, and touch history at this immersive Civil War hospital.

The Grand Ole Opry's big voice came from a small home in rural Virginia where she was eventually buried.

An overgrown collection of miniature buildings still stand as evidence of one couple's obsession with The King.

The Virginia home of one of the signers of the Declaration of Independence is being preserved with a unique glass facade.

The Virginia farm where John Wilkes Booth met his grisly end is now largely forgotten.

At 207 feet, one of the world's longest continuous escalators.