Loreto is a city and municipal seat of Loreto Municipality, Baja California Sur, on the West Coast of Mexico. Located on the Gulf of California, the city had a population of 16,311 inhabitants in 2020. Loreto is a regional economic and cultural center, as well as a major tourist destination on the Baja California Peninsula.

The Gulf of California, also known as the Sea of Cortés or Sea of Cortez, or less commonly as the Vermilion Sea, is a marginal sea of the Pacific Ocean that separates the Baja California Peninsula from the Mexican mainland. It is bordered by the states of Baja California, Baja California Sur, Sonora, and Sinaloa with a coastline of approximately 4,000 km (2,500 mi). Rivers that flow into the Gulf of California include the Colorado, Fuerte, Mayo, Sinaloa, Sonora, and the Yaqui. The surface of the gulf is about 160,000 km2 (62,000 sq mi). Maximum depths exceed 3,000 meters (9,800 ft) because of the complex geology, linked to plate tectonics.