Topanga State Park is a California state park located in the Santa Monica Mountains, within Los Angeles County, California. It is part of the Santa Monica Mountains National Recreation Area.
The park is located adjacent to the community of Topanga, within the City of Los Angeles. Covering 11,000 acres (45 km²), with thirty-six miles of trails and unimproved roads, the park’s boundaries stretch from Topanga Canyon to Pacific Palisades and Mullholland Drive. There are more than 60 trail entrances. Topanga State Park is not only the largest park in the Santa Monica Mountains, but it's also considered to be the largest park located in the limits of a city.