A whimsical monument deep in this park commemorates the groups that helped build it.

One of the earliest bowling lanes in the U.S. doubled as a sewing school during a time when women had little job opportunity.

A morbid secret lies hidden within the beautiful walls of the Boston Athenaeum.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

An abandoned Gold Coast-era mansion once intended for the exiled ruler of Albania, who never arrived.

Forgotten under the construction of a new urban roadway is a small, abandoned part of town.

Underground tunnels remain beneath this abandoned mental asylum.

A reliquary of pop culture marvels, including the world's largest (and most terrifying) Jack-in-the-Box.

An abandoned 146-acre summer resort slowly being reclaimed by nature.

An overgrown and abandoned tuberculosis ward resides in the midst of a quaint modern neighborhood.

The remnants of a 19th-century ironmaking complex hidden in the woods of Connecticut.

Connecticut's shot tower is near the end of its life.

The US Navy's only submarine museum is also home to the world's first nuclear submarine.

More than a century of radio history is told in these displays.

Ruins of a historic medical facility sits eerily by the water.

A former copper mine which became a truly unsuccessful prison.

This abandoned psychiatric hospital once housed more than 4,000 patients in the middle of a quaint New England town.

Overgrown ruins of a turn of the century island fort that sees very few visitors.

An alley way dedicated to graffiti and street art is a constantly changing street gallery.

This railroad tunnel was once the longest in Massachusetts.

From economic backbone of a community to deadly diving hole, these former stone quarries are now a park for rock climbers and graffiti artists.

The bears may be gone, but their old cages can still be found.

A cave dug by a man directed by ghosts to find pirate treasure.

The ruins of a Massachusetts prison farm can still be found crumbling the woods of a state park.