The massive machine creates cracking displays of indoor lightning.

On top of Gibbet Hill lie the ruins of a lavish turn-of-the-century estate that never quite came to be.

This miniature feudal castle was built on a whim to honor a US Navy pioneer.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

An eccentric inventor's castle home with its own indoor weather system.

A lonely memorial to the Challenger Space Shuttle, honoring the astronauts who died in 1986.

Maybe the only missile installed in a public park, this Cold War leftover was one of the first to carry a nuclear warhead.

Once America's longest-manned military fort, now an abandoned hulk.

A beloved upside-down beacon off the coast of Northern Ireland.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Unrepaired walls from a 1920 anarchist bomb attack.

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

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

A massive forgotten storehouse from 1913 on the Brooklyn Waterfront has a spectacular view of Brooklyn.

The longest continuous underwater road in North America was built at the insistence of Franklin Roosevelt.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

The home of the first American-born saint is one of the only curved buildings in New York.

Two distinctive homes on a New England village green look like a couple of frosted wedding cakes.

The monument dedicated to Phineas Gage in the town where his accident happened.

The remains of a deserted 1800s farming community can be found in Little River State Park.

This large cemetery is known as the museum of granite sculptures.

Cryptid lake monster honored with its own monument.

Industrial ruin decimated this tiny New England company town in a fashion no one saw coming… and even fewer remember today.