The Hudson River School comes alive at this palatial estate.

This stone gatehouse was once the entrance to a historic mountain resort, and it had a cameo in a cheesy cult horror movie.

The oldest continuously inhabited street in America.

America's first serial killer rests in anonymity.

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

The final resting place of one of the United States's greatest poets.

A completely round house designed for the Atomic Age.

Current docking place of the SS United States, the fastest transatlantic ocean liner.

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

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

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

A clone-tree in Washington Square Park sprung from seeds that went to the Moon and back.

In the early 1800s, surgery was also a show.

A curious building honoring past and current members of a historic musical comedy troupe.

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

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.

Huge masonic hall in Philadelphia with lavishly themed rooms.

This beloved marketplace mascot poops money and grants good luck.

Time travel with sweets across history at this research-based candy store.

Built in the 1850s, this church was of the first five churches constructed in Harper's Ferry.

This shale formation along the Appalachian Trail once inspired the third president of the United States.

This advertisement for talcum powder was painted on the rock face and has since defied removal.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.