Mandeville Canyon is a north-south running trench in Brentwood area of the Santa Monica Mountains. Above Mandeville Canyon is San Vicente Mountain, a 1,960-foot summit that was used at the start of the cold war as a defense site to protect Los Angeles from Soviet attacks. Mandeville Canyon is enclosed by two long finger-like ridges, Westridge and Canyonback Ridge. There are trails running down each ridge that can be reached via fire road from Mandeville Canyon Road, which runs down the center of the residential canyon. These trails can be used to explore the upper stretches of Mandeville Canyon and San Vicente Mountain Park, creating a 5-mile loop with 770 feet of elevation gain.
San Vicente Mountain was one of several summits around Los Angeles used as a Nike missile defense site in the 1950s to detect and intersect Russian missiles and aircraft directed at the city. After a decade, Nike missiles were made obsolete by long-range technology, but the Santa Monica Mountains Conservancy has done an excellent job preserving this old site, adding informative panels to keep this history alive. There are several benches and tables spread out around the old buildings, along with restrooms and a water fountain, making San Vicente Mountain perfect for a picnic.