This might just be the TARDIS of bookstores.

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

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

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

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

The fastest transatlantic ocean liner sat abandoned in a Philadelphia shipyard for decades.

Yo, Adrian!

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

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

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

Dr Barnes' $25 billion private collection of art and arboretum.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

Huge masonic hall in Philadelphia with lavishly themed rooms.

The world’s first penitentiary, meant to be humane, drove men insane.

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

Mural made of 100,000 pieces of hand blown glass, and one of the largest glass murals in the US.

The pits used to load the nuclear bombs onto the aircraft that dropped them over Hiroshima and Nagasaki at the end of World War II.