Mugu Lagoon is a salt marsh located within the Naval Base Ventura County at the foot of the Santa Monica Mountains in Ventura County, California. The lagoon extends for 4.3 miles parallel to a narrow barrier beach. The first European to come ashore here was Juan Rodríguez Cabrillo on October 10, 1542. Cabrillo was the first European to visit present-day California, and he named the lagoon Mugu after Muwu, which is Chumash meaning "beach" or "seashore".