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

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

Huge masonic hall in Philadelphia with lavishly themed rooms.

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

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

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

This sculpture of a fisherman spent six years at the bottom of the Schuylkill River.

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

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!

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