Death Valley, California. At 282 feet below sea-level, Death Valley is one of the most inhospitable places in California—nay—the United States. Temperatures in the hottest time of year can regularly exceed 120 degrees Fahrenheit. In fact, at 134 Fahrenheit, Death Valley maintains the highest temperature on record. While the Valley of Death has little to offer besides a place to hide where nobody will bother to look, it was also a good place to mine borax.