Obsidian Butte on the Salton Sea

California's ghostly Salton Sea was once a popular tourist spot, but now is so salty it can't sustain life. This deadly lake makes for some strange environments. Bodies of birds and fish that can't take the salt wash up on shore, and the arid sand surrounding the water is dotted with leftovers from its life as a fishing destination. 

The Salton Sea is also bookended by giant obsidian buttes which predate the manmade lake by maybe as much as 8,000 years. These ungainly domes add another element of unearthliness to the alien landscape. The buttes were born around 6,000 and 0 BC, out of the volcanic activity beneath California's tectonic plates.

The obsidian ranges in color from chalky white to dusty gray to shiny black. Visitors are free to take obsidian samples for themselves, but due to the salinity of the environment the obsidian generally isn't dense enough.