Remains of a historic fountain that was mysteriously lost in the demolition of a D.C. traffic circle.

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

A winding district gerrymandered into the shape of a mantis.

A hidden alley in urban Baltimore is a haven for graffiti artists.

Housing the National Women's Party since 1929, this historic house is now a monument to the fight for gender equality.

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

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

Electronic inventions that resulted in products and systems we use every day are on display in this labor-of-love museum.

The lost town of Neversink, sunk by New York City.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

A much-maligned monument to teetotalism.

Near-constant high winds deform the trees on Spruce Knob, the highest point in West Virginia.

The highest point in Maryland is only accessible by hiking through another state.

"Only the devil could play golf here."

Little Red Lighthouse under the George Washington Bridge.

The highest point on the island known for buildings that touch the sky.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

The only remaining building in New York to see the inauguration of a president is being slowly overtaken by a grocery store.

The rough and tumble president's childhood home displays the shirt he was once shot in and the speech that saved him.

New York City's smallest piece of private property.

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

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

An interesting decoration on this historic site, this weathervane comes with as many legends as it does questions.

A famous songsmith's custom piano, dubbed "High Society," is hidden just out of sight in one of New York's finest hotels.