Take a Walk in a Park

Now, for those who are bereft of "yard", there are other options. The most obvious of these options are parks. Certainly there will be one fairly close 
to where you live. Maybe more than one. Pick one out and go there. Hang out for a while. Do the same as what you would have if "yard". Make a day of it.

Uh... I said "walk". It'd be best if no vehicle was involved. This is in order to show you that our cities and towns are very poorly planned. (I'm 
talking about the US here. Other places may have faired much better, I suppose. I've never been to those places, though, so here we are)