An easy-to-miss plaque marks the building that first held this 19th-century telephone innovation.

This icon of the Atomic Age now lays dormant.

These disused steel furnaces are now haunting ruins that may one day be a national park.

The Paul Bunyan of the steel industry.

An ode to filmmaker George A. Romero, who used the mall to film an iconic horror movie.

The Pennsylvania shopping center was once the setting for the 1978 film, "Dawn of the Dead."

The juke joint where legendary soul artists ate, drank, and made merry.

Elvis's own personal tropical hideaway.

This Memphis recording studio launched the careers of Jerry Lee Lewis, Johnny Cash, and Elvis Presley.

Home to drunken tower-climbing goats... seriously.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

This brick-lined pedestrian walkway was once a railway tunnel used during the Civil War.

This colonial tavern played host to George Washington, Thomas Jefferson, and other famous early Americans.

The narrowest house in America is seven feet of pure spite.

An original apothecary from 1792.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

A replica of the famous memorial statue at the Normandy American Cemetery hides in an office building in downtown D.C.

This taxidermy horse was a Civil War hero.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

This nine-story building is the oldest standing skyscraper in D.C.

An overlooked memorial honoring the local Washington residents who died in World War I.

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.