I've fished here many times below the falls, under the old Roman Bridge and down in to the deep gulley leading to Dunning Glen, but don't try that now, not without scuba gear because all of that racey little section of the river Devon and a bit of acnient history were flood out when the Castlehill Dam was build to create the reservoir. I've fished the reservoir too, it was a bit dour on the day and I suffer from vertigo. On the day I took the photographs the water was cascading over the the dam creating a spectacular waterfall and just knowing that drop was there left me feeling queezy, weird or what? Enough of that.
The loch fishes well for brown trout and rainbows, there are also d some very big pike and perch. It is smallish but deep. I remember the glen was steep moving up to the narrows which was a deep gully, smaller but similar to what you see at Rumbling Bridge downstream.
There are boats and bank fishing looks to be limited by the steep banks and bankside vegitation
Castlehill Reservoir 07399 676546
Google Map Reference: 56.208530, -3.609659