Trarza is a region in south-west Mauritania. Its capital is Rosso. Other major cities and towns include Mederdra and Boutilimit. The region borders the Mauritanian regions of Inchiri and Adrar to the north, the Mauritanian region of Brakna to the east and Senegal to the south (to the west is the Atlantic Ocean). The Mauritanian capital Nouakchott and the capital district are geographically part of the region.