The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

A monument celebrating the idea of reaching inaccessible places.

This bridge over D.C.'s Rock Creek Park is sometimes called the "Buffalo Bridge" because of its four buffalo sculptures, which were cast from a single piece of bronze.

Hidden within an idyllic suburban garden is a memorial dedicated to the victims of a terrifying spree of killings committed on U.S. soil.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

She stares out across six lanes of traffic, clutching a musket and infant with determination.

The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

An intricately designed junk art house with four extravagant junk art cars hidden in the suburbs.

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

A crumbling hospital from the 1850s on Roosevelt Island.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Site of the first pathological and bacteriological research facility in the United States.

One of only two commuter aerial tramways in the United States.

On this island, you suck away your garbage via an elaborate pneumatic tube system.

A sculptural commentary on capitalism pokes up from the East River.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

A little lighthouse in New York City, surrounded by mysterious stories of insanity-driven construction.

The first pet cemetery in the United States.

A tribute to the beloved, kind-hearted "homeless mayor" of Silver Spring.

Built in 1945, this historic train station has a new lease on life with its baggage area serving as an event space.

A benevolent, 16-foot-tall river dragon lives on a suburban lawn.