Rivas, city, southwestern Nicaragua, on a narrow strip of land between Lake Nicaragua and the Pacific Ocean. Founded in 1736 and formerly known as Nicaragua, Rivas gained fame as a town on the “Vanderbilt Road,” over which Americans joining the California Gold Rush traveled from the adjoining lake port of San Jorge to the Pacific port of San Juan del Sur. In 1856 a battle in the war against the American filibuster William Walker was fought there. Rivas is a commercial and manufacturing centre in an agricultural area; tanneries, dairies, and plants manufacturing rubber items are located in the city. It lies on the Pan-American Highway, which links it to Managua, the national capital.
Most of the inhabitants of the surrounding region are concentrated in the region’s central valleys. The valleys are important for livestock raising and sugarcane, coffee, cacao, corn (maize), beans, rice, and tobacco. Pop. (2005) urban area, 27,650.