Rivière Noire is a district on the western side of the island of Mauritius. Rivière Noire translates to Black River. This region receives less rainfall than the others. The district has an area of 259 square kilometres (100 sq mi) and the population estimate was 80,939 as of 31 December 2015. It is the third largest District of Mauritius in area, but the smallest in terms of population. The district is mostly rural, but it also include the western part of the city of Port Louis and western part of Quatre Bornes.