A dozen U.S. presidents have stayed at the historic resort, which was known as James Buchanan’s “Summer White House” from 1857-1861.

Beautiful views of the surrounding hills and birds of prey can be found at this sanctuary.

A field of nothing but boulders which resembles a giant's gravel driveway.

This Pennsylvania cave holds evidence of the oldest known inhabitants of North America.

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

In the bowels of a 19th-century brewery lurks a fine-dining restaurant offering an array of themed feasts.

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

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

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

This might just be the TARDIS of bookstores.

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

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

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

A beautiful oddities shop crammed with strange and morbid curiosities.

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

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

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