we do trips to the shopping centre too - especially around Christmas time - the dds (dd1, 5, ASD, dd1 - 3, NT) love looking at the displays and trees.
then a snack on a bench ( odd child dd1 loves benches)
and yes, playgrounds and swimming.
it's a wonder we don't all know each other already - we all hang out in the smae sorts of places!
I have been known to make a trip out along the lines of: inventing that we need something dd1 is obsessed with (paperclips being the most obvious one I recall). so all in the car - quick chat about which shopping centre to go to (dd1 chose)
get there, walk around all the shops selling paperclips so dd1 could help choose which ones we needed
coffee break while we decided which ones to buy (coloured stripey ones, iirc) back to buy them, and then home again.
the whole trip took about 2 hours.
and then I felt less guilty about retreating while they watched cbeebies etc, as at least they had been out of the house that day...