Earl Warren Dog Park
4660 Crow Canyon
Castro Valley, California 94546
This is a nicely maintained small dog park, that offers separate play areas for smaller or senior dogs. It also offers water stations, poop bags (you should bring your own, sometimes they run out) benches and shade.If you have a small dog whom you wish to socialize.
There is a small dog meetup here every 4th Saturday of the month around Noon (weather permitting).