The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

This Delaware River bridge is emblazoned with a catty slogan from a more prosperous time.

This strange, big-tailed beast became a Pennsylvania town's unofficial mascot.

A pride of the state, this working museum crafts pottery mosaics in the style of Pennsylvania's earliest European settlers.

South Philadelphia is home to Keith Haring's only surviving in situ collaborative public mural.

An Irish Memorial commemorating those who perished due to potato blight.

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.

This jail which was in service for over a century is now open for curious visitors.

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

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

A historic covered bridge is but one example of an oddly prevalent American urban legend.

The remains of a community that was forced to move for a dam that never materialized still rot in this Pennsylvania park.

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

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

A mine fire has been burning under the deserted town since 1962, but this church is still going strong.

In which a local geological marvel becomes a quaint roadside attraction.

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

Eccentric concrete mansion and museum designed and built by hand from the inside out.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

A toxic ghost town sitting atop a massive coal fire.

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

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

Millions of numbers carved in glass represent the tattoos forced upon victims.