The walls of America's oldest masonry fort famously "swallowed" cannonballs.

Arrr! The most authentic collection of pirate artifacts in the world... matey.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

The first piece of public art dedicated to LGBT rights.

Those belting out show tunes in this West Village piano bar might not realize it marks the site where Thomas Paine died in 1809.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

An extensive collection of fine art devoted to man's best friend.

An homage to Jackie Gleason's bus-driving character from 'The Honeymooners.'

This statue of one of baseball’s greatest pitchers looks like something out of a sci-fi horror movie.

Mural fragments and various sculptures honor the longtime artist.

A more than 260-year-old crypt built on Boston's oldest English burial ground.

This statue intended for children to enjoy became a minor political spat.

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

A men’s restroom became a sandwich shop.

Dedicated to one of the darkest moments in Irish history.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

Millions of numbers carved in glass represent the tattoos forced upon victims.

This nearly 200-year-old restaurant's history includes an exiled French prince, JFK, and a very hungry Daniel Webster.

Statue commemorating the use of ether in anesthesia.

A monumental statue of RCA's mascot now sits atop a historical society roof after a life of moving around.

A museum dedicated to exhibiting remarkable outsider art.

A 200-year-old bar with a cheeky name claims to have served Edgar Allan Poe his final drink.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

This spot memorializes one of the greatest plays in NFL history, unless you happen to be a Raiders fan.