So we set off to walk all round the lochan, perhaps foolishly on a day when we'd had 14mm of rain overnight. We left the car by the recycling point, crossed the Millburn, and walked directly north, over a low hill, to find ourselves looking down on a waterfall made spectacular by the overnight rain.
This is a view of the lochan - sadly with no swans on it - from the opposite side, looking back towards Meall Chro Bheinn and the way we had come. The Sanna road runs between the hill and the lochan.
....which gave us another fine view of the waterfall, this time in bright sunlight.
To make matters worse, when we'd almost reached the recycling point, we found that this fence crosses the Abhainn Chro Bheinn, meaning that we either had to cross that burn, which was running strongly, or climb over the barbed wire. We plunged into the burn.
An interactive version of this map is here.