Woodland Hills is in the southwestern area of the San Fernando Valley, east of Calabasas and west of Tarzana. On the north, it is bordered by West Hills, Canoga Park, and Winnetka, and on the south by Malibu. Some neighborhoods are in the foothills of the Santa Monica Mountains. It was in this area that the treaty was signed to end the Mexican War, clearing the way for California to be admitted to the union as the 31st state. In the '20s, the town's first developer imported over 120,000 trees, which later inspired the community's name. On the western boundary is the large Upper Las Virgenes Canyon Open Space Preserve, a regional park with a trail network providing miles of hiking, mountain biking, and equestrian rides. To the south are many parks in the Santa Monica Mountains National Recreation Area. The Top of Topanga Overlook affords panoramic views of the verdant Woodland Hills neighborhoods and the Valley. Woodland Hills is home to the famed Motion Picture & Television Country House and Hospital, exclusively for industry professionals. The core of the business district is Warner Center, a master-planned development built on the site of movie mogul Harry Warner's Warner Ranch.