Photo by Jim Luhr, 1990 (Smithsonian Institution). Volcán Sudoeste, one of a group of young pyroclastic cones of the San Quintín volcanic field, is located at the head of a narrow peninsula jutting into the Pacific Ocean. Volcán Sudoeste, seen here from the north, may have initially been an island. The sand bars along the coast, formed by longshore currents, connect Volcán Sudoeste to Monte Mazo, at the southern end of a 10-km-long sand spit.