Five Canyons Open Space is located in Castro Valley, in Alameda County, California. Five Canyons is a multi-agency collaboration between East Bay Regional Parks District, Alameda County Public Works, Hayward Area Recreation and Parks District, and several homeowners associations. EBRPD is the lead agency for this open space. FCOS opened in 1998, consists of 300 acres and 5 miles of trails and has almost no amenities. The main visitors are hikers, bicyclists, equestrians and dog walkers.