This is the main type we've got here:
Fit for Parks - Outdoor Gym Equipment for Public & Community Park

If you look at Locations, you can see approx. where to find them:
Locations


Evidently, these are located in the US too:
Outdoor Fitness Equipment Featured Installations

And these:
Greenfields Outdoor Fitness Equipment


But if you do a search for Outdoor Fitness Equipment, you'll find heaps and heaps of sites, the three I've linked to above are just random examples out of so many. These things are everywhere, and so convenient to incorporate into a long ride.