Fifty years after a “blast blasted blubber beyond all believable bounds,” this idyllic natural area commemorates the carnage.

World's largest cave was only discovered in 1991, and now offers tours to the public.

A volcanic landmark located on an Ice age lake bed.

A volcanic fissure over two miles long and up to 70 feet deep.

An apocalyptic seismic event creates a deadly chain reaction that ends with a 6-mile long lake developing within weeks.

When the Austin Dam failed it destroyed much of Austin...and then it failed again.

The remains of the dam that unleashed a 15-foot wall of water on Denver.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Secret Manor, a house full of legends, the least of which is the haunting of long-deceased ladies of pleasure.

This former boomtown "island" is now submerged below Folsom Lake.

The tale of a strong-willed woman who stood her ground when the commercial world came rumbling in.

Cave carved out of a huge snow drift collapsed killing one and injuring five in July 2015.

This long, dark tunnel is open to hikers, but those without lights are known to get confused even on the straight path.

A cave interior in the shape of the ancient rhinoceros, created by lava cooling around its carcass.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

This granite monument at the site of an ill-conceived tourist attraction is built from the same stone as the Mormon Temple.