Maryland's first (and last standing) toll house on America's first federal road established the state as the "Gateway to the West."

A tradition unlike any other, this marks the site of the annual Groundhog's Day tradition.

Memorializing an American tragedy of massive proportions.

This pair of eccentric Ohio castles were built by a pair of brothers who wanted to bring a bit of class to the Ohio wilderness.

In this relatively flat state the highest point is an honored place.

These sub-farmland caves are home to a majestic stalactite known as the "Crystal King."

This beautiful stone arch bridge wasn't even expected to stand for one day, but people have been crossing it for centuries.

Where the oil industry began.

Frank Lloyd Wright’s most iconic home dangles over a Pennsylvania waterfall.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

Pennsylvania's own Roswell-style UFO mystery.

The inventor of a number of hybrid corn species is immortalized with a field of giant corn.

It took more than 20 years and a sharp eye for one man to assemble this quirky collection.

A bronze of the man in all his sinewy glory celebrates his longtime connection to the Ohio city.

This moving cemetery sphere is a slowly rolling stone.

Featuring one of the most complete and original collections of Presidential memorabilia, this is the site of the last front porch presidential campaigns.

This presidential tomb was not dedicated until years after Harding's death due to personal controversy.

This shrine to McDonalds' most iconic sandwich holds a 14-foot tall burger.

This Old Testament garden features 100 plants from biblical times.

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.

The largest university building in the West is a gothic masterpiece containing dozens of theme rooms based on different countries.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

All that remains of a gigantic earth-moving machine.

The pop art icon's gravesite is broadcast 24 hours a day on his museum's website.