Del Valle Regional Park is a park of the East Bay Regional Park District (EBRPD) in unincorporated Alameda County, California, south of the city of Livermore. The park is 4,316 acres (~17.47 km2., ~6.74 sq. mi.) big. There are many prominent and locally famous cliffjumping locations around the lake including The Rock, The Swallow Bay Cliff, and The Pillars. All can be accessed through various trails surrounding the park. The park can be approached from Mines or Arroyo Road, where the parking meter is often broken.