Someone needs a pre-arranged place in a busy city where they can dodge out of sight for a few minutes, or even less. They won't be staying there for any length of time, but they need to be confident that the space won't be in use when they go in. It has to be somewhere they could have observed in advance as being suitable for this purpose. It can't be somewhere they would have to pay to enter.
This is normally the sort of thing I'm good at, but my mind's just going blank, and I can't think of the right words for the sort of place I'm almost-but-not-quite imagining. Possibly because I've used some of the obvious possibilities before. Also I'm a little loth to say "an abandoned/derelict wherever" (though I'm fine with saying a gate is always carelessly left unlocked) because it's just a bit too convenient and this is a large modern city, close to the centre, and there can't be that many derelict buildings standing around. It's morning so some space connected to a business that won't open until late could work, or somewhere in a car park...? (But are car parks usually further out of the centre of cities - forgive me, I don't drive, and am evidently experiencing a brain-outage.)
I don't think there should be any parks or gardens nearby. Not big ones, anyway.
I really can't think Google will help me with this, though I did try things like "hiding places city" and image searches with "yard, bins" which was obviously no use at all. I have consulted the less-useful-than-it-sounds book "Places To Hide."