This fertility idol of questionable authenticity inspired an iconic Indiana Jones artifact.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

A much-maligned monument to teetotalism.

Sit where JFK proposed to Jackie or where Nixon dined on meatloaf at this storied pub.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

A clone of a cloned tree that was so important it allegedly had its own guards.

When it opened during the final years of the embargo, all the drinks and cigars were free.

There’s a hidden military meme engraved on the World War II Memorial.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

A room in New York City that contains 250 cubic yards of dirt worth a million dollars.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

The mummified relics of an American missionary.

The gilded vestiges of a sterling department store can still be found in a Brooklyn shopping center.

Failed state-supported institution meant to rehabilitate students with intellectual disabilities.

A one-ton statue of Steve Rogers beautifies the entry to a Brooklyn Bed, Bath & Beyond.

A mysterious, abandoned building rotting on the Brooklyn waterfront.

A prohibition era watering hole for the police.

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

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.