A daily replay of the experiment that proved the rotation of the Earth.

Behold the rickety glory of one of the oldest roller coasters still standing.

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

This elaborate towering structure was once famed for its revolutionary height.

An outlandish shoe shaped house built by an eccentric millionaire.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

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

There aren't too many operational funiculars around, but Pittsburgh has two!

The first American department store, and home to the largest operating musical instrument in the world.

Eccentric concrete mansion and museum designed and built by hand from the inside out.

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

The United States’s oldest funicular railway glides up and down a steep Pittsburgh street.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

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

A toxic ghost town sitting atop a massive coal fire.

Most of this “research national monument” still lies buried beneath the earth.

This depiction of the earth mother welcomes new life into Aurora Highlands.

Meet Rita the Rock Planter, one of Danish sculptor Thomas Dambo's enormous wooden trolls.

This Colorado fire station has been in continuous operation for more than a century.

See 150 million-year-old dinosaur tracks and bones dating back to the Jurassic period.

One of few remaining antique carousels with stationary animals in the U.S.

A dangerous narrow-gauge railroad once traced a route through this striking canyon.

Overlooking the Colorado Convention Center is this giant sculpture made from thousands of triangles.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.