A neighborhood of houses made of poured cement through a process invented by Thomas Edison.

This vintage short line in Amish country runs passenger steam train excursions and still hauls freight.

This giant, rotating globe was built to celebrate the expansion of a company that makes steam cleaners and pressure washers.

Believed to be the birthplace of the United States Marine Corps.

The penultimate and final resting places of British General Edward Braddock—minus a few bits and pieces.

Color-coded signs direct drivers on a network of routes designed to avoid Pittsburgh traffic.

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

Francis Julius LeMoyne built this crematory in 1876; he was the third person to be cremated here.

The Pennsylvania shopping center was once the setting for the 1978 film, "Dawn of the Dead."

An eccentric priest's tribute to George Washington, this chapel tells the story of the American Revolution.

Memorializing an American tragedy of massive proportions.

The site of the little-known Pennsylvania battle that sparked the Seven Years' War.

This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

Don't get it twisted: This is the oldest pretzel bakery in the United States.

This dramatic rail curve was once the target of a failed Nazi attack.

What looks like a simple quaint estate in rural Pennsylvania was in the 18th century home to a small monastic community.

Nothing says indulgence like a 1,500-pound chocolate castle.

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

Step into a pastel time capsule where candy is truly dandy.

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

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

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

Yo, Adrian!

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