My grandparents live in Castro Valley. If you know of anywhere out there that would be fun, I would then have an excuse to visit my grandparents, and vise versa, and excuse to already be in Castro Valley to do parkour.
Hi Jeremy, if you can make it over to Berkeley we train there every week on Thursdays. Although it's not exactly structured like a class, me and several others will be totally willing to help you get starting and get the basics down if you joined us. Let me know if you want more info on that. Unfortunately I'm not sure if anything regular happening in Castro Valley.