Closest we have are bodyweight exercise parks - and they are not nearly as common as they should be.

Sure, no slides or seesaw, but monkey bars for dayz.

Edit: Also, y'all remember parkour? IIRC somewhere in the annals of history there's a design for an adult jungle gym built with Georges Hébert's fitness philosophy in mind (more jungle gym-ish than military obstacle courses). Vaguely remember seeing a translated book with the design. Anyway, some of those, please.