Bunny, it sounds like it's the one. From Cwmbach you pick it up just after the Total Petrol station and you can then either walk around the top of the Ynys (when that path is not flooded) or emerge around 200 meters before the Aberdare fire station.

There is some history along that footpath Bunny, there are Concrete pillars not far from the Cwmbach entrance, which supported the old railway bridge over the canal, the railway line went to Abernant, and serviced the Abernant number 9 colliery, and the Werfa colliery.
Further along you come to the footpath leading to the Ynys and Aberaman, which goes under the railway bridge, which underneath always holds water in wet weather.
By the turn off, the canal head and docks are by there, there used to be a hand opperated crane, and docking bollards, for the barges, I expect it's all silted and weed covered now, just after the turn off there used to be benches for to sitting on.
If you carried on you would come out near Plasdraw.
Opposite that entrance there used to be a pavillion. With outdoor bowling green's and tennis court.
You would have to be a brave woman to walk there on their own, with the nutters that are around today.

I used to use this path regularly years ago and it was a lovely, peaceful place to sit and while away the time. Now, however I'd be very wary to walk along it on my own due to the apparently mindless idiots that congregate there. They may be perfectly innocent but they still seem very intimidating.