Waiau Ferry Bridge
Shortly before Hanmer Springs, you cross the Waiau River on the Waiau Ferry Bridge. This crosses a gorge high enough above the river to allow bungy jumping. There is a cafe and parking area just before the bridge as well. If you drive over the bridge towards Hanmer Springs, there is another place you can park that looks up the gorge to the bridge and down the river to the west.
You can access all the normal river activities as well – jet boats, rafts etc – and there is a campground down by the river.