Ash Meadows Wildlife Refuge boasts the largest concentration of unique and endangered species of plants and animals in the United States. The Devil's Hole Pupfish is probably the most famous of these endemic creatures found here, but there are a vast array of beetles, snails, and flowers that are not found anywhere else on the planet. Although on the edge of Death Valley and right in the middle of the Mojave Desert, the refuge is a world of its own and truly a natural wonder. Nature enthusiasts and photographers will not want to leave!
If you go:
There are no entrance fees. All the roads to and within the refuge are unpaved but mostly well maintained. There are three boardwalks in the main habitat areas that are wheelchair accessible. Swimming is permitted in Crystal Reservoir, but nowhere else.
Links:

610 East Springs Meadows Road
Amargosa Valley, Nevada 89020 USA
desertcomplex@fws.gov
Phone Numbers:
Ash Meadows Visitors Center
+1 (775) 372-5435
+1 (775) 372-5435