Where in the world?
The flag of Mauritania has a green field with a thin red horizontal band at the top and bottom of the field. At the center of the field is a five-pointed yellow star above an upward facing yellow crescent.

Islamic Republic of Mauritania

Native name: MauritaniaPopulation: 4,649,660Region: AfricaSub region: Western AfricaCapital: NouakchottTop level domain: .mrCurrencies: Mauritanian ouguiyaLanguages: Arabic
Border Countries:AlgeriaMaliSenegalWestern Sahara