Reclaimed by nature, the ruins of Doodletown, New York are remnants of a town consumed by a state park.

Inside, ancient treasures. Outside, modern contradictions.

A small granite block at this monument's base is the only part of Lincoln's Tomb outside of Illinois.

This abandoned iron furnace was one of the first to use coke—a type of high-carbon fuel—to make iron.

It marks the spooky spot where the bodies of two young boys were found in the 19th century.

The creek where a shark wreaked terror upon New Jersey, and served as the inspiration for "Jaws."

This Central New York ghost town was once a prosperous railroad community.

The lost town of Neversink, sunk by New York City.

This once luxurious Catskills resort is now a haunting ruin.

Once the world's largest reinforced concrete structure, this abandoned bridge now beckons urban explorers.

The final resting place of the Hollywood star who came to a tragic end.

A tradition unlike any other, this marks the site of the annual Groundhog's Day tradition.

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

Contrary to what one might expect, ice forms inside this small cavern during the summer and melts during the winter.

Yo, Adrian!

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

The home and studio of a visionary woodworker now stands as a museum and example of his artistic genius.

This secluded walking trail is a hidden gem of a Pittsburgh park.

These disused steel furnaces are now haunting ruins that may one day be a national park.

An 18th-century Catholic church converted into an eccentric temple of music and bacchanalia.

The Pennsylvania landscape depicted by a quarter mile of mosaics made from used road signs.

This Philly landmark has a giant butterfly pavilion, three floors of insect displays, and withstood a $40,000 heist.

America's first serial killer rests in anonymity.

The residents of the Neighborhood of Make-Believe live without much fanfare within the Pittsburgh Children's Museum.