TBH I've always been surprised that it's free. It's not the swing park (although that's the photo I've seen attached to the report - bit sneaky) it's the separate Adventure playground which you access through that bit. Last time I went it was staffed, so I assume this charge is to go towards their salaries?
Seriously, I'd normally be the first in line to denounce Tory cost-cutting, and it would be lovely to beat them over the head with this, but it has been blown up into something larger than it actually is. There's still plenty of free stuff to do 