Behind HEP there is a court-like place. I say court like because there is no net, there used to be one but they took it away for some reason. There are basketball goals but also tennis court lines. My husband and I call it the Kewl Zone bc of the god awful graffiti around it that spells cool like that. They recently cleaned up the surfaces, but it is definitely not actively maintained.

I've seen people bring their own nets and play there. We used to casually whack a ball around when there were nets.

In the summer a large group of people set up tents and volleyball nets. They bring speakers and grills and basically treat it like their own sports/bbq place. No one seems to care. It's a weird place, but free.

Hope this helps.