The walk from the Control Gates to Rainbow Reach Bridge is on the Kepler Track, one of New Zealand’s great walks. Instead of following the lakeshore, take the path that follows the Waiau River south. While the walk has some slight gains and descents in elevation, it is mostly flat and walks through lush green bush. This difference in elevation allows you to walk alongside the river and, at other times, stand closer to the tops of the tall red beech trees. Most of the time, you will have to crane your neck to see the top, but this walk takes you just a little higher up every so often where the forest floor is slanted.
There are a couple of wooden bridges on part of the Kepler Track that pass over streams flowing down the mountain, but the most interesting bridge is definitely Rainbow Reach Bridge at the end of the walk. It is a swing bridge over the Waiau River. The bridge is elevated about 5 or 6 meters above the river. The quality and clearness of the water is incredible. Standing on the bridge on a clear day, you will be able to see the mountains to the south. There is a car park at Rainbow Reach Bridge so you could do the walk the other way.
While you’re in Te Anau, make sure you take a day trip out to Milford Sound. Or take a once in a lifetime scenic flight over Dusky and Doubtful Sounds. which leaves right from the waterfront in Te Anau.