Problem
It is a mark of success in a park, public lobby, or a porch, when people can come there and fall asleep.
Solution
Keep the environment filled with ample benches, comfortable places, corners to sit on the ground, or lie in comfort in the sand. Make these places relatively sheltered, protected from circulation, perhaps up a step, with seats and grass to slump down upon, read the paper and doze off.
Related Patterns
… this pattern helps to make places like the Interchange (34), Small Public Squares (61), Public Outdoor Room (69), Street Cafe (88), Pedestrian Street (100), Building Thoroughfare (101), A Place to Wait (150) completely public.
Above all, put the places for sleeping along Building Edge (160) ; make seats there, and perhaps even a bed alcove or two in public might be a nice touch - Bed Alcove (188), Seat Spots (241); but above all, it will hinge on the attitudes which people have - do anything you can to create trust, so that people feel no fear in going to sleep in public and so that other people feel no fear of people sleeping in the street.
Reference for full-text of Pattern: p. 457low-confidence