Self-built house and sculpture park where the creator can still be seen in a glass coffin.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

This ancient structure is widely thought to be the oldest intact pyramid in the world.

The English Civil War began right here in 1642.

The largest oak in England is said to have been the hideout of Robin Hood and his Merry Men.

The ancestral home of beloved English poet Lord Byron has a bizarre history.

An enigmatic natural rock formation with a manmade passage cut through the center.

When it came to designing his own small office building, the eccentric architect wasn't afraid to show the world what he could do.

This unchanged Victorian park is rumored to have been the inspiration behind Peter Pan's Neverland.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

The remains of the man who founded Pennsylvania lie in an unassuming grave in the English countryside.

Human-made caves excavated to hide a secret society of wealthy pagans.

America's smallest national park site is the former residence of exiled Polish national hero Thaddeus Kosciuszko.

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

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

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

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

Yo, Adrian!

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.

A museum dedicated to the strange and extravagant costumes and memorabilia of the mummers, a tradition older than Philadelphia itself.

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.

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