I dragged my fiancee to the hottest and driest place in the country...Death Valley National Park. I had a little trouble convincing her it was really God's country but after seeing all these spots she came around ;o)...
This is Badwater - 282 feet below sea level (the lowest point in North America). All that white stuff is salt - they call it the Salt Pan. Obviously Badwater gets its name from the salty water that is undrinkable.
Many Sand Dunes are found in Death Valley.