I don't think I have seen a park that looks like a gym. Do you mean people bring their gym equipment there?

A lot, majority, of local parks in China cities, which are largely apartment living, have outdoor areas with various iron equipment like dips and pullup bars, rowing, basically calisthenics, and spaces for older people to do synchronised dancing or taichi. Benches (for sitting, not presses). Quite communial. A big positive if stuck in an apartment. But the park doesn't look like a gym and not a lot of the frames will be occupied, but if you want it, it's invariably there and pretty social; all free.

A park nearby has installed workout equipment along the trails. Basic outdoor swing-set type stuff but a real bummer when you want to enjoy natural scenery. Most parts of the trail are concrete slabs now instead of dirt...

It’s just gym equipment that’s designed to be durable outdoors. Kind of like jungle gyms but for adults. I’ve seen it in Cape Town, Milan, London, Auckland and always they are busy.

I have seen that, yes. Those jungle gyms are generally on a flat piece of grass that normally would be open and also relatively small. I thought it was more of a proper park - think full of bushes, trees, ponds, trails, birds etc. I haven't seen jungle gyms in places like that, which of course would be detrimental to the nature.