Being in a playground while adult and male!
Being in a playground while adult and male!
(Similarly, if you're 40 years old, you can't go to the public kindergarten. It's because the program is designed to educate 5-year-olds, not 40-year-olds. Nothing to do with sex, it's merely practicality.)
If that IS the case, we have bigger problems.
With a simple rule change you wouldn’t even have to change anything about the playground layout. Just allow unaccompanied adults playing chess and nothing else and the problem is solved.
Amending the sign to read something like "no adults, unless playing or watching chess, but not if a child has been waiting to play, except ..." would get complicated fast. Just go to a different park already.
British Airways recently had to admit they had a secret policy of moving men seated next to other's children on flights. It only came up when they moved Boris Johnson from sitting next to his own kids, they didn't realise they were his own children - presumably they looked human (although you have to wonder if the kids were secretly relieved)