Sections of the iconic limestone columns have been left uncleaned as a reminder of the city's polluted past.

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.

Once the most painted on object in the world, this short campus fence is well on its way to being so again.

A pride of the state, this working museum crafts pottery mosaics in the style of Pennsylvania's earliest European settlers.

A model of a dinosaur that was named for Andrew Carnegie stands outside the museum that also bears his name.

Board a mine car and descend the #190 slope 300 feet underground into the Clark Vein of coal.

The remains of a community that was forced to move for a dam that never materialized still rot in this Pennsylvania park.

An indoor miniature village and labor of love for Laurence Geiringer, a model railroad enthusiast.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

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

These tourist trap caverns are said to be the former home of a legendary Pennsylvania Hermit.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

This hospital fell into ruins after failing to act as the advocate for the mentally ill it was designed to be.

Infamous marsh filled with toxic waste, World War II-era London rubble, and dead mobsters galore.

The highest point in New Jersey is marked by a massive, if simply named, obelisk.

One of New Jersey's oldest surviving buildings still bears the mark of our former British overlords.

Historic town settled in the 19th century because of its convenient location along a popular coal transport route.

A world-class collection of mechanical musical instruments and automata.

During the solar phenomenon "Lahaina Noon" this bendy, curvy sculpture forms a perfectly circular shadow on the ground.

Take shelter from Hawai'i's tropical heat under the massive canopy of largest Banyan tree on the island.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.