Manning Gorge is located on Mount Barnett Station, about half way along the Gibb River Road. Access is via the Mt. Barnett Roadhouse.
The roadhouse is very well equipped, well set up and offers good service and a basic campground. This is also where you pay your entrance and camping fee for Manning Gorge.
(You pay that first, and then you drive on for a few more kilometres to the camping area and gorge.)
On my very first Gibb River Road trip, Manning Gorge was one of the most memorable gorges, for several reasons:
We were there early in the season and the falls were still flowing strongly, cascading over the full width of the rocks.
It was late in the afternoon. And while that had a disastrous effect on the photos I took (directly into the sun was the only option) ...
... it meant we had the whole, big gorge to ourselves.
I also thought the walk to get to the gorge was great, but I've heard others complain about the long, hot walk.
The walk to Manning Gorge and the Manning Gorge Falls starts from the campground.
The beginning certainly is not hot, because first you have to cross the Manning River. In the old days you had to swim across the pool and float your stuff across in the provided styrofoam boxes. Or you walked around to wade across further upstream, criss-crossing the deep creek several times, of course on slippery rocks, treacherous logs, mud etc. Always good fun to watch others do it...
These days there is a dinghy and an endless rope so you can pull yourself across and stay mostly dry.
After that the walk is open and sunny, but the scenery is beautiful. You
can't get lost, because the track is so well marked with hundreds of
rock cairns and red disks and arrows and beer cans and all sorts of
other markers strung into the trees.
It is a narrow, rough and rocky track that occasionally climbs up and down, so it makes sense to wear sturdy shoes, like I do.
To get to the gorge you have to hike for about 3 km.
The gorge itself is huge and you can easily spend hours exploring it. It has several pools to swim through and rocks to climb up and over.
You can also climb to the top of the waterfall.
If you want to see the waterfall cascading over the full width of the rocks, as it's shown in most pictures of Manning Gorge, then you need to be there early in the season. It dries up fast.
But the pools are deep. They are always there, always cool and clear, and you can swim all year round.