Hey Guys, I saw the google map with places to play in the South Bay, and East bay, but are there any (e.g. high school) open gyms or badminton places cheap or free, in the City proper? (San Francisco)?

Sadly I have no access to a vehicle, and paying public transit to get to Bintang or BayBadminton would be pricey and take a long time, only to pay more to actually play, then pay and wait to get home when finished

Intermediate level, been playing twice weekly for about 5 months. Thanks in advance!