On Sunday morning we went to Bois de la Batie, a little animal park over near Lancy. We drove. The closest the tram gets is the circle in Jonction, at the bottom of the hill, which we didn't feel like walking up with little kids. The alternative from the right bank is to walk or cycle through St Jean, and then cross the Rhone on the railway bridge. From here you can look down on the confluence of the Arve and the Rhone and you get a great view of the city as well.