Guess where?

Windy Gap?

Looks like Sterkhorn is set to let us sweat this one out over the weekend. So I may as well throw another waterfall in - the one you see from Ndedema cave. I haven't been to the edge there, so this guess is out of coverage rather than insight. The prospect of Windy Gap raises a great artifice - best since van Heyningen's.

Mnweni Cutback and the Ndedema option are also incorrect. It is actually further north and a lot less remote than the last few suggestions. I do have a couple more pictures taken a little further up-river, which might be easier to recognise. I can post them if you wish?

As to "Windy Gap", even though I have been caught in a massive thunderstorm in that area on the pass, I did not even then see that amount of water in the Gap.

Relieved it wasn't windy gap !
what about the falls near near the chain ladder?

What about inner tower gully in the amphitheatre?

No, it is not the Elands (near chain ladder), nor is it the inner tower gully.
Here are the other pictures from a little further up the gully, which may help

That's a lot of water for the high berg! Unless Tugela gorge fits in somewhere (though the rock isn't smooth enough - in fact it looks like the flow in the gully is unusually strong), I'm fresh out of ideas. Intrigued to know where this is.

Bilanjil Falls it is. Well done . I'm surprised it was not figured out sooner. I thought that area would have been explored more. For those that are intending visiting the Amphitheatre in October, that area is well worth a visit, if not a rewarding alternative to camping in the usual Tugela basin.
Besides the interesting Bilanjil Falls, it also provides an interesting perspective back to the top of the Tugela Falls.
Below is a picture taken from the buttress opposite the Bilanjil Falls - if my memory serves me right, there are about 3 levels from the first rapid till the actual waterfall.