Los Peñasquitos Canyon Preserve, Nature reserve in San Diego, United States.

Los Peñasquitos Canyon Preserve is a 4,000-acre urban park in San Diego, jointly owned by the city and county. It stretches about 7 miles through Peñasquitos and Lopez canyons. The photograph shows large pale gray and tan boulders with brownish rusty patches, piled in stepped, rounded forms with crevices and ledges; sparse dry brown grasses and small green plants grow in the gaps, and dark water lies at the base of the rocks near the right side.

The Rancho Santa Maria de Los Peñasquitos adobe was built in the early 1820s, when the land was under Mexican rule. The County of San Diego operates the restored home and offers public tours. The preserve is jointly owned by the City and County of San Diego.

The name Los Peñasquitos means "little rocks" in Spanish, referring to the rocky outcrops in the canyon. The Rancho Santa Maria de Los Peñasquitos adobe, built in the early 1820s, is operated by San Diego County and open for public tours. Visitors can see the restored adobe and the rock formations the name describes.

Entry is free and the grounds are open daily from sunrise to sunset, with parking at several entrances. The trails are well-marked and suit different fitness levels, with some sections shaded and others more open.

The preserve is jointly owned and run by the City and County of San Diego, and at about 4,000 acres it ranks among the 50 largest urban parks in the United States. Its roughly 7 miles of canyon shelter over 500 plant species and more than 175 kinds of birds; a rare mountain lion attack occurred here in May 2019.