One of only two commuter aerial tramways in the United States.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Elevated freight railway turned wildly successful urban park.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

A crumbling hospital from the 1850s on Roosevelt Island.

The only remaining piece of hull of the most decorated US ship of WWII is this giant name plate.

A discreet little stairway on St. Nicholas Avenue leads to a quaint and unexpected cobblestone street of 19th century wooden rowhouses.

The remains of the furnace and iron works that produced the massive Hudson River Chain still stand in the woods of New York.

A secret, rocky playground hidden amongst the plain white beaches of the Florida coast.

Manhattan's deadly West Side railroad, which killed hundreds of New Yorkers, is remembered by this simple plaque.

An isolated beacon with a history of grisly murder and a view of some of literature's greatest inspirations.

This plot of old-growth forest is the largest surviving remnant of New York City's original woodland.

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

Self-sufficient greenhouse floating on the Hudson River.

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

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

This North Carolina museum is keeping the pinball craze alive, with a little Space Invaders on the side.

This giant iron playfully pays tribute to an early 20th-century architectural trend.

The U.S. Supreme Court's secret Cold War relocation facility in the mountains of North Carolina.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

One of the oldest living oak trees in the Southeast.

The final resting place of one member of the Amistad slave revolt who never made it back home.