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

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

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

The oldest surviving botanic garden in the United States.

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

Enormous lake at the bottom of a unique cave system.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

Mysterious rocks that ring musically when struck.

A layered tribute to the work of mosaicist Isaiah Zagar.

A toxic ghost town sitting atop a massive coal fire.

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

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

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

An artsy hidden staircase leads to breathtaking views of San Francisco.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.