A scenic fort on the harbor protected Philadelphia from an attack that never came.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

Current docking place of the SS United States, the fastest transatlantic ocean liner.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

The first American department store, and home to the largest operating musical instrument in the world.

A layered tribute to the work of mosaicist Isaiah Zagar.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

An Irish Memorial commemorating those who perished due to potato blight.

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

Huge masonic hall in Philadelphia with lavishly themed rooms.

World Trade Center memorial likened to a woman's sexual organ.

Infamous marsh filled with toxic waste, World War II-era London rubble, and dead mobsters galore.

19th century cemetery hidden in Brooklyn's Prospect Park.

Lie in a hammock where George Washington stood.

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

On the Hudson resides one of the largest clocks in the world.

Named the fifth most beautiful building in America in 1885, this former courthouse boasts the best view in the Village.

Elevated freight railway turned wildly successful urban park.

Steepest flood safety railway in the entire world.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

A train station that was abandoned by the coal industry and was later converted into a cocktail bar.