Ad-Dakhla or simply Dakhla is the biggest city in southern Western Sahara It's a crossroads for all travel trough Western Sahara and most traffic between Morocco and Mauretania will stop here. Dakhla is a famous spot for kitesurfing, just outside the city is a big camping ground and several lodges for kite surfers.
Hitchhiking out to anywhere
The vastness of the desert and the sparse traffic might seem intimidating. But from the few cars there are, a lot will stop for hitchhikers and most of them go long distance.
To start out, hitch from the city of Dakhla to the highway, which is further inland. You'll reach a desolated roundabout with a tiny gas station. From here you can thumb in south direction to reach Mauretania or to north direction to reach El Aaiun and Morocoo.