Some of the East Bay Regional Parks are open, with social distancing restrictions. Also water fountains and restrooms are closed. The situation seem to change daily, so I would suggest visiting their website: https://www.ebparks.org/ I also noticed there is a Rattlesnake Advisory Warning in effect.
The website contains virtual tours, although you have to download and app for your phone. You can find the videos in their Digital Learning Center, which also contains a number of videos. The district maintains a Youtube channel, with these videos and more. You can find it at: https://www.youtube.com/user/ebrpd94605. You might want to pass along the URL to people who are home schooling.