This forgotten boat elevator was an engineering marvel in its heyday.

These recently uncovered walls are all that's left of Washington, D.C's first defense contractor.

A derelict bit of transportation infrastructure hidden in the woods.

Descend 2,030 years into the past in an ancient tunnel built to support Jerusalem's most famous wall.

Hidden beneath a washing machine in a fake kibbutz, this secret bullet factory has been preserved as a museum.

These old doors are covered in the signatures of Rehoboth Beach artists dating back to the 1930s.

A wrecked ship dating back to the American Revolution was only recently discovered off the Delaware coast.

WWII-era bunkers are hidden under the beaches of this picturesque park, which is still scattered with wartime watchtowers. .

The ruins of this long-abandoned unsuccessful gold mine can still be found.