Established in 1798 by Father Fermin Francisco de Lasuen, San Luis Rey de Francia Mission, the 18th of California, was one of the most important. Find out all about its history on a tour of the museum established in a long gallery. You will then reach a small inner courtyard overlooking the church on one side and the cloisters on another. Outside, head for the ruins of the soldiers' camp, washhouse and aqueduct.