I don't understand this answer. Why is the "right thing" to do, to ask "Can I ?". When that's not necessarily a prerequisite, in the first place ? Ie.: That's only begging the question at-hand-here Ie.: Isn't that the very thing we are discussing ? Who said you
"couldn't", in the first place ?
For things like this, and for innocuous benign parks, the problem with asking desk-jockies "Can I ?", is that you can often run into the "No one cared
UNTIL you asked" psychology.
And then sure, you might fetch a "no". But does that mean anyone would have cared or given 2 sh#ts ? Probably not (until your "pressing question").
There was rows and rows of military housing and barracks slated to be torn down, at an Army base near me. And like the O.P. Describes : Signs on the buildings said "No trespassing". We helped ourselves to the lawns, no problem. One time though : A security guard M.P. guy started to raise a fuss, pointing to the signs. We merely assured him that we were out front (by the sidewalks) and not in the buildings. Thus obeying the signage. He just shrugged his shoulders, and drove off. We continued hunting.