The largest burial mound in the United States holds the remains of prehistoric West Virginians.

The museum calls itself the "National Museum of the Paranormal" and is full of eerie oddities.

Despite its lavish ornamentation, and wholesome lifestyle of its devotees, this mountain commune has faced its share of issues.

Despite being stolen multiple times, this civic electrician's street corner Snoopy won't be stopped.

The last street in Pittsburgh that's paved with wood.

A quiet, gothic haven nestled between Pittsburgh's Squirrel Hill and Point Breeze neighborhoods.

This historic Pittsburgh tennis complex is a rare example of natural red clay courts.

This beacon for pre-radar pilots once guided Charles Lindbergh to a safe touchdown in Tulsa.

The legacy of baseball great Roberto Clemente is preserved in a retired Pittsburgh fire station.

After covering almost 1.5 billion acres, the survey's still not finished.

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

The only statue of its kind to commemorate Washington's beginnings as an officer of the British Colonial Militia.

An American flag was erected for every day that passed during the Iranian Hostage Crisis.

The Pennsylvania landscape depicted by a quarter mile of mosaics made from used road signs.

Where the oil industry began.

Priceless space junk on display in front of a local Dairy Queen.

This historic mansion was built as a symbol of love between a husband and wife.

Edgar Allan Poe's old dorm is now a shrine to the author's legacy.

The ruins of this Thomas-Jefferson-designed mansion have been left to crumble since the Christmas Day they burnt down.

Collection of antique science instruments displayed in recreated 1870-1930 laboratories.

Quite possibly the last cross all humans will ever see.

This unique crypt designed by Frank Lloyd Wright for his longtime friend was not completed in either man's lifetime.

The absurd creation is a compulsory destination for selfies in Buffalo.

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