A tree grown from astronaut seeds which were exposed to cosmic rays.

This remarkably simple jail went over a century without an escape.

The stately birthplace of California's statehood.

This eagle-topped spire remembers the military commander who snatched up California for the United States.

The oldest U.S. Government building in California, and it's State Historic Landmark #1.

The first safe in this California town had to hold all the gold.

The oldest continuously occupied public building in the United States.

The headquarters of the semiconductor giant has a 10,000-square-foot museum.

The largest underground pedestrian tunnel system in the U.S. mostly caters to the people working in the offices above, but provides a great, air-conditioned way to traverse the city.

A symbol of Texas pride.

This massive oak tree has ties to the first native tribes of the region and the founders of Texas.

The final resting place of infamous outlaw Clyde and Marvin Barrow.

Nature has shaped this drainage tunnel into the digestive tract of a mighty beast.

This pristine World War II airfield gives a comprehensive look at atomic development and aviation history.

This magnificent natural sandstone bridge is one of the largest in the world and is an iconic symbol for Lake Powell.

This open-pit mine is now an abandoned symbol of Bisbee's copper-mining heritage.

This sinkhole in the Arizona desert is filled with carbonated, arsenic-rich water

This mesmerizing and surreal landscape features intricate patterns of white and red sandstone.

The cinder cone volcano with a less than complimentary name.

What began as a prominent Burning Man art piece is now an iconic symbol of downtown Reno.

What once housed a private club catering to Comstock Lode elite is now considered one of the West’s most haunted spaces.

The museum is housed inside the historic 1863 Carson City Mint.

A stretch of highway even lonelier than the so-called "Loneliest Road in America."

These markers are used to document elevation changes around the famed dam.