The Wollangambe River passes through numerous sections of canyon on its way to the Colo River. The two most popular sections lie below Mt Wilson, and are excellent lilo trips on a summer day. The notes below describe the upper tourist section, often called Wollangambe 1.
Note that despite the grade of "Easy", getting to and from the canyon still requires a descent and ascent of over 300m on a track that is steep and rocky in places. The exit requires an exposed climb up tree roots. The canyon itself involves many long, cold swims, for which lilos and wetsuits are recommended, and there is a significant amount of climbing up, down and around house-sized boulders. Make sure you are fit and have appropriate gear before you go. There is no phone coverage.
Also, the time estimate of 5 to 7 hours is for a "moderately fit and experienced party of around 4-5 canyoners, including a couple of experienced leaders". Many groups will have inexperienced members, and will likely take longer - times of up to 10 or more hours are not uncommon.
Park at the fire station at Mt Wilson, and follow the fire trail around behind the fire station. Turn left on to another fire trail at the T-junction after 200m. Past the top of the hill, the main trail swings right and then crosses another fire trail. There is a sign to the Wollangambe River at the head of a foot track opposite that you should follow. At about 2km a track branches left below a large (10m) sandstone outcrop. Avoid this and continue past another sandstone pagoda on your left. As you near the river, the track swings sharply left. Head upstream along the cliffs above a gully for 200m until you can climb down a steep corner on tree roots into the gully. Follow this down to the river at MGA546914.
Follow the river downstream. There are many long deep pools, so lilos and wetsuits are advisable. There are a number of points early on where you can climb up the cliffs on the side of the canyon for jumps to about 8m. Check the depth carefully. Further down there are a few large boulder scrambles to negotiate. There are no abseils.
The usual exit is found at a beach (MGA560916) with a gully coming in on the right. NPWS have installed a small sign with a black arrow on yellow background pointing the way. Climb up the right hand side of the gully, and then up rocks and tree roots (a bit exposed). Follow the track back to a fire trail. Turn right (green sign with arrow points the way) and follow this back to where another sign points left to Mt Wilson, and from there back to your car.
Alternatively continue downstream past a 2m scramble or jump (be careful if you jump) to the sharp left hand bend at MGA563916 and climb up to the right. This track joins up with the other track above before it hits the fire trail.