San Diego de Alcalá is a historic mission located in San Diego, California. Founded in 1769 by Father Junípero Serra, it was the first of the 21 California missions. The mission played a significant role in the Spanish colonization of California and aimed to spread Christianity among the Native American population. The mission features a beautiful church and gardens, reflecting the architectural style of the period. Today, it serves as a museum and a place of worship, attracting visitors interested in California's history and the mission system. It is also recognized as a California Historical Landmark.