Eccentric concrete mansion and museum designed and built by hand from the inside out.

World's first "penitentiary," meant to be humane, drove men insane.

This enormous banquet-themed artwork honors over 1,000 notable women throughout history.

This might just be the TARDIS of bookstores.

This strange, big-tailed beast became a Pennsylvania town's unofficial mascot.

The one-time office of the architectural firm that ushered in the Gilded Age is now a Club Monaco.

A trove of century-old litho stones from the Puck Building's printing days were discovered behind a cellar wall, and are now hanging in the store.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

This once-grand marvel of engineering is now 41 miles of scenic hiking trail.

A field of nothing but boulders which resembles a giant's gravel driveway.

The headquarters of one of the world’s longest-running humor magazines bears a noticeable resemblance to a head wearing a Prussian helmet.

The thousands of shades on display — some toxic, others impossibly rare — are a library of more than just color.

The first piece of public art dedicated to LGBT rights.

The vaguely man-shaped root that ate the body of the founder of Rhode Island.

This blue behemoth of a bear is a colorful homage to Brown University's mascot.

An architectural statement of artistic intent smack in the middle of Providence, Rhode Island's Colonial uniformity.

Books bound in human skin and H. P. Lovecraft's letters are among a few of the treasures this library has to offer.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

Visit the monolithic tomb of America's most famous general.

A curious fountain that has no water and includes Satan, a crab, and 9 giraffes.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

The "Seinfeld" diner.

Built just after the American Revolution, the oldest row house in New York City still stands in Chinatown.