A priceless collection of the Nation's cryptologic history.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

The U.S. government built the million-pound stack of steel during the Space Race.

Two dozen pinball games hidden away inside a most unlikely location.

This recently restored crypt was once plagued by liquefying coffins and exploding caskets.

Medical history with an amazing, if frighting, collection of wax diseases on display.

Accessible only at low tide, the deserted island is dotted with World War II ruins.

Statue of death tucked in the University of Medicine courtyard.

This museum houses an imposing skeleton army comprised of creatures great and small.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

The land is home to swimming ponies and a legendary 18th-century treasure.

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

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

This stately mansion, built in 1787 by America's first Secretary of the Navy, is rumored to be one of the most haunted buildings in Washington, DC.

An Industrial Revolution-era public work that purified water using nothing but sand.

A painfully obvious spy house sits right across the street from the Russian Embassy.

Hidden in a Scotland museum is a copse of extinct tree stumps.

Hut with supplies for shipwreck survivors.

A cave dug by a man directed by ghosts to find pirate treasure.

The walkable ruins of an 19th century hotel, destroyed in a horse cremation gone wrong.