This popular Castro Valley swim complex is only a short drive north from Interstate 580 on Cull Canyon Road in Castro Valley.

The lagoon won the 1966 Governor’s Design Award for Exceptional Distinction for Recreational Development in the category of landscape.

When the swim area was constructed, a secondary dam was built to provide an inner swimming area complete with a sandy beach. Never previously tried, this innovation made the swim area water level independent of the reservoir’s, unaffected by summer draw-downs. The reservoir no longer exists south of the swim area.