This groundbreaking 16th-century map is known as "America's birth certificate."

Believed to be the birthplace of the United States Marine Corps.

WWII-era bunkers are hidden under the beaches of this picturesque park, which is still scattered with wartime watchtowers. .

A planned settlement in Pennsylvania once housed the aristocratic refugees of the French Revolution.

The remains of a community that was forced to move for a dam that never materialized still rot in this Pennsylvania park.

One of the U.S. Forest Service's only mansions is outfitted with a dinner table for floating food.

The final resting place of many of New Jersey's most famous residents, including U.S. history's most in-vogue antagonist, Aaron Burr.

These unassuming lighthouses have seen the first reading of the Pledge of Allegiance, the first wireless transmission, and more than one mystery.

The highest point in New Jersey is marked by a massive, if simply named, obelisk.

Historic town settled in the 19th century because of its convenient location along a popular coal transport route.

Vacant Beaux-Arts buildings that serve as reminders of a beach town’s glory days.

Local lore claims this park is named after a young woman who jumped off a cliff.

Edison's cast-in-place concrete houses were a failure, but way ahead of their time.

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

This old-fashioned candy shop, ice cream parlor, and diner served as the setting for one of TV's most controversial series finales.

The final resting place of one of the United States's greatest poets.

World War II bunker still standing on the New Jersey beach.

One man's lifelong obsession with death.

A reservoir of vintage pinball machines and arcade games for the nostalgic and thrill seeking.

Step inside Lucy, the world's largest "elephant."

The remains of a 19th century spring, and the site of an infamous unsolved murder.

Along the Palisades skyline are the ruins of a large mansion built in 1911 and demolished in the 1930s.

The site of one of history's most indelible and horrific tragedies.

Once in a state of dilapidation, this candy-inspired fortress is now being revived.