The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

An allegorical sculpture in Maryland wears the artist’s politics on its trunk.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

One of the oldest of its kind.

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

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

The body of St. John Neumann and his collection of hundreds of relics, on display in a Philly church.

A layered tribute to the work of mosaicist Isaiah Zagar.

Century-old shop, specializing in Occult products.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

A daily replay of the experiment that proved the rotation of the Earth.

This elaborate towering structure was once famed for its revolutionary height.

World's first "penitentiary," meant to be humane, drove men insane.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

Yo, Adrian!

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

Steepest flood safety railway in the entire world.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

A monument marks the location of the first successful steamboat demonstration.