The major airlines have offices in Nouakchott. Mauritania Airlines has flights to Nouâdhibou (UM31,000, 45 minutes) daily, except Wednesday.
There are specific garages for Mauritania's different regions.
For Nouâdhibou (about UM5000, six hours), several companies including Premiere Classe, Le 28 Novembre, Gulf Transport and Prince Voyage, are all clustered together in a traffic-clogged mess on the N2 (Autoroute Nouâdhibou), just north of the intersection with Ave Gamal Abdel Nasser. Other companies with service to Nouâdhibou have small garages in the l'Ksar Gare Routière neighbourhood near the old airport a few kilometres east of the centre.
For Rosso (about UM2500, 3½ hours), Garage Rosso is at Carrefour Madrid, a roundabout southeast of the centre; less comfortable taxis are the same price.
For Atâr (UM6000, six hours), Garage Atâr is on the road to Atâr, about 3km north of the airport.
The Ksar Gare Routière, near the airport, serves destinations to the southeast including Kiffa, Ayoûn el-Atroûs and Néma. You should also be able to find bush taxis to Tidjikja from here.