Pennsylvania's own Roswell-style UFO mystery.

A piece of baseball history is preserved in a Pittsburgh parking lot.

A portion of the old Pirates stadium over which a defining home run once flew still stands even after the rest of the stadium was torn down.

A museum commemorating the Donora Smog, which killed 20 people in October 1948 and sparked national outrage over air pollution.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

Built in the 1850s, this church was of the first five churches constructed in Harper's Ferry.

This striking Victorian Home with its 113-foot turret is best known as the site where abolitionist John Brown was executed in 1859.

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

This monument marks the beginning journey of a wounded soldier's leg that ended up almost two states away.

The sign to a demolished amusement park now stands in front of a local library.

An unassuming store hides relics of its former life as the jazz club that hosted some of the best black performers of the 1920s and '30s.

One-of-a-kind preserved ruins of an abandoned 1880s church in Chicago's Pilsen neighborhood.

A hollow cement depiction of time's inexorable effect on the human body.

The original Garfield station is the oldest station facility on the "L", with the station house dating from 1892.

A plaque marks a former safe house on the secret route, now hidden next to a McDonald's.

The clothes-washing king doubles as a community center with some unusual features, including an aviary filled with finches.

Chicago was once a major hub of film production, but being silent film you don’t hear much about it.

The mortal remains of a Russian prince, priest and paranormal investigator who came to America in 1792.

This bridge was constructed from the remains of the first Ferris wheel.

This grave marks the final resting place of pioneer John Chapman, better known as Johnny Appleseed.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

When you visit his grave, be sure to rub the Great Emancipator's nose for good luck.

The empty tomb that houses the memories of Roy Bertelli's revenge.

The original vault that held the president's remains still stands, empty, not far from where he was finally buried.