The locality of San Luis is located to the northeast of the department of Rocha, on the coasts of the Río San Luis and next to the route 19, in the kilometer 29, about 150 km of the departmental capital. The name of this place has its origin in a Jesuit priest, Luis Costanza, who arrived in the area by the year 1650. A century after his death, the Catholic Church canonized him and later the town was renamed San Luis al Medio.
This region, mainly devoted to the cultivation of rice, also conserves marshes of varied fauna. The Cerritos de Indios also abound, testimonies of the life of the oldest inhabitants of these lands.