Whilst briefly in London, I stumbled across this chap sleeping in Green Park (aptly named) near Buckingham Palace.
I recently spent a week in Darwin and was surprised to see many more long grass people than I was accustom when I left Darwin 20 years ago. Long grass people (predominantly indigenous Australians) live without housing, in the parks in and around Darwin. Anyone who has been to Darwin will know that during and after the wet season, the grass in some of these park areas is quite high. I am not sure if the problem is worse, maybe I became oblivious to long grass people when I lived in Darwin.
So it seems that parks (with grass) are a good place to rest, no matter where you are in the world.