Kiffa is surprisingly spread out for a town of its size. Walking between the market, the main road, and the residential areas takes time in the heat. A taxi or shared ride is the practical option for getting between different parts of town.
For excursions outside town — particularly to the canyon east of Kiffa — you need a 4x4 and a local driver. Bush taxis occasionally run east toward Nema and west toward Nouakchott; shared departure times are unpredictable and based on demand. If you are crossing Mauritania on the Route de l'Espoir, carry extra water and fuel beyond what you expect to need — services are scarce between towns.