Galleta Meadows Estate in Borrego Springs, CA...about an hour and a half East of San Diego. Lots of great videos about it online, but here's some info to get you started:Very cool! Where is this?
Exploring the Metal Sculptures of Anza Borrego and Galleta Meadows - California Through My Lens
Don't miss the video embedded in this blog as well. I know you are in Alameda, but definitely worth seeing if you are ever down in this area.