Old Town San Diego State Historic Park is a state protected historical park in the Old Town neighborhood of San Diego, California. The park commemorates the early days of San Diego; it includes many historic buildings from the period 1820 to 1870. The park was established in 1968. In 2005 and 2006, California State Parks listed Old Town San Diego as the most visited state park in California. In 1969, the site was registered as California Historical Landmark No. 830.