Beautiful video John. What a great location. Do have a question.... on the left wall as one faces the falls there appears to be a white square man-made object... At first I thought it was a wayward drone but clearly it isn't. (You can see it clearly in the last 30 sec of your video.) And as always thanks for sharing. By the way your 63 year old brain seems to be in pretty good shape!!
Never noticed it before, in fact there are three of them and all the same shape. I wonder if they are water level indicators, but they are way too high for that. Odd. Come Autumn here downunder, I will go back to the amazing place and take a closer look. You are right they do look man-made.