With 3,000 bikes on display, the world's largest bicycle museum includes some famous rarities.

It would take 35 firetrucks to fill this enormous glacial pothole.

This stone tower marks a lookout point over the historic Washington Crossing, and maybe some buried treasure.

The pop art icon's gravesite is broadcast 24 hours a day on his museum's website.

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

This park contains a number of standing stones meant to heal and inspire.

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

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

When the Austin Dam failed it destroyed much of Austin...and then it failed again.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

Once the "Eighth Wonder of the World," this iron railroad bridge was decimated by a tornado.

This might just be the TARDIS of bookstores.

A park full of outsider art, created by college students studying outsider art.

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

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

A stone arch leads to a cavernous 1930s spring house tucked away in the Pennsylvania woods.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

Huge masonic hall in Philadelphia with lavishly themed rooms.

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

Found art has transformed this Pittsburgh neighborhood into a psychedelic dream.

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

Mysterious rocks that ring musically when struck.

A toxic ghost town sitting atop a massive coal fire.