The Sweetwater Marsh is a 300-acre wildlife refuge within 10 driving-miles of the Tijuana River Valley. The visitor’s center provides exhibits, guided nature and bird walks, a shark and ray exhibit, and the opportunity to view native birds in outdoor aviaries that support burrowing owls, shorebirds, egrets, and herons. The park does not have equestrian trails, only hiker trails. http://www.fws.gov/sandiegorefuges/Sweetwater.htm