A beloved horticultural oasis on the grounds of a wealthy family's former estate.

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

Designed by Horace Trumbauer in 1893, this Gothic-style castle is now a home for academics.

Where the famed frontiersman was born, raised, and survived Quaker intrigue

A "house to which to flee" for settlers in colonial Pennsylvania.

Inside this 150-year-old barn turned antique shop is a vast array of items for curios hunters.

This historic furnace was once used to produce cannonballs during the Civil War.

This stately 19th century library pushed architectural boundaries at a time when the public library movement was just taking off.

Descendants of this colonial Pennsylvania family still travel from far and wide to visit the 300-year-old home of their Quaker ancestors.

This colonial mansion has been home to a staggering number of American historic figures.

America's smallest national park site is the former residence of exiled Polish national hero Thaddeus Kosciuszko.

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

An otherwise quiet campground becomes a bustling medieval town for two weeks every year.

An ideal wedding spot that is almost too ideal.

A planned settlement in Pennsylvania once housed the aristocratic refugees of the French Revolution.

A rock maze opens up to a panoramic viewpoint at an abandoned mine full of ghost stories.

One of the oldest log cabins in America is one of the last of its kind this historic Swedish dwelling remains a piece of living history.

This semi-spooky remnant of an abandoned hotel provides fantastic views.

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

America's first serial killer rests in anonymity.

The Home and murder site of the witch of Rehmeyers Hollow.

The ruined remains of a coal mining ghost town are hidden within the woods.

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

The headquarters of the Fraternitas Rosae Crucis, complete with Rosicrucian pyramids, all in the Pennsylvania woods.