I am a desert known for its unique 'fairy circles' and diverse wildlife, including the elusive desert-adapted elephant. My temperatures can fluctuate drastically, with scorching days and freezing nights, making survival challenging for most. The fog that rolls in from the nearby ocean provides some relief to my inhabitants. What am I?

1. My name translates to 'place of vastness'.
2. I am considered one of the oldest deserts in the world.
3. I am known for having some of the tallest sand dunes on the planet.
4. I am primarily located in southwestern Africa.