Bac Lava: A scramble along the foot of coastal cliffs aided by stainless steel chains bolted into the rock. I went with my two sons at the end of summer at around mid tide.
The Firth's water was exceptionally clear and there were a number of pools well suited to plunging. We had forgotten our swimsuits but with no one else around, there was no option other than to remove our (metaphorical) kilts for a truly exhilarating experience. The place we had most fun was the arch near Chain 5.