A remnant of the original World Trade Center complex continues to serve as a commuter gateway.

Opened in 1956, the first modern indoor shopping mall in the world was inspired by the shopping arcades found in European cities.

The first museum in the United States dedicated entirely to posters.

A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

This eclectic sculpture garden in Brooklyn, home to a bizarre collection of art, was once a run-down junkyard.

This striking arch, one of the first architectural elements constructed in Prospect Park, was recently restored to its original glory.

America's oldest Eastern European synagogue provided the immigrants of crowded Lower East Side tenements a space of sanctuary.

Take a step into the workshop where Edison and his employees revolutionized the world.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

This abandoned factory on the Hudson River once churned out a million bricks a week.

A 19th century hat factory still stands as a crumbling ruin in upstate New York.

The remains of what was once the world's steepest passenger funicular.

This abandoned ironworks was once the most important military supplier in America.

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

Reforestation in action is the main attraction in this abandoned quarry.

Astonishing collection of helmets, scientific instruments, and medical models.

New York's unstoppable progress turned this cemetery into the smallest burial ground in the city.

Hidden in one of New York's oldest subway stations is the final remnant of the site of the bizarre Shakespeare Riots.

This theatre and its amazing marquee harken back to the Golden Age of Hollywood.

Seven people are buried in the middle of what's now a movie theater parking lot.

Nassau Hall has served as army barracks, a museum, and played a key role in the American Revolution.

The mysterious canine hides atop a drain pipe on the back of the building, some say as a sneaky shoutout to Yale.

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

American involvement in World War I officially ended in 1921 in New Jersey, three years late and thousands of miles from the battlefield.