El Aaiún is a city in Western Sahara, and for 99% of cases signposted and named as Laayoune.
South to Boujdour, Ad-Dakhla, Mauritania
Get yourself to the direction of the airport. Along this road, just some meters behind the airport, you'll find a petrol station and the city's end. Behind the petrol station it's perfect to stop cars, though quite some locals might hitchhike here as well. The next police checkpoint is situated about 2 km further, and it's also no problem to take a ride only to the port (25km), from where you can hitch easily as well (there's only one road anyway). If you are lazy, a taxi ride to the spot from the city center costs about 5 dirham (~45 Eurocent) for 2 people (August 2010).