This 30-foot pile of rocks may be the grave of a mythological Irish queen.

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

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

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

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

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

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