Ponte Velha is the old one-lane metal bridge over the Nhundiaquara, restored in the 1970s and now one of the town's easy landmarks. It is not grand, but it frames the riverfront nicely and puts you right among the restaurants and old houses.
Cross on foot if traffic is light. From the bridge you get the simple Morretes view: river below, church tower and tiled roofs nearby, forested Serra do Mar behind.