This hidden library of physiological ephemera contains centuries worth of knowledge on the vim and viscera of the human body.

This castle-like building in Manhattan helped destigmatize cancer in the 19th century.

Once considered a marvel of engineering, this 107-mile canal played an integral role in building New York City.

On the Hudson resides one of the largest clocks in the world.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

This tiny man looms large over downtown Charleston.

Although built to generate electricity for Marylanders, this dam has become an all-you-can-eat buffet for American bald eagles.

This sculpture of a fisherman spent six years at the bottom of the Schuylkill River.

Yo, Adrian!

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

A curious building honoring past and current members of a historic musical comedy troupe.

Century-old shop, specializing in Occult products.

A layered tribute to the work of mosaicist Isaiah Zagar.

This elaborate towering structure was once famed for its revolutionary height.

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

One of the oldest active carousels in the country—but it might be missed by all but the keenest-eyed boardwalk strollers.

This building at the south end of the boardwalk was once home to the U.S. Life-Saving Service and the U.S. Coast Guard before being rescued itself.

This statue is dedicated to Grace Sherwood, the last person in Virginia to be convicted of being a witch.

The flower-shaped temple in Virginia aims to transcend the boundaries of the world’s religions.

This claimant to the title of "smallest church in the 48 states" doubles as an equally tiny, quasi-post office.

The rusting remains are visible sticking out of the waters of the Delaware Bay.