I've seen a handful of Marsh Tits over the years whilst delivering the post in Henllan so I thought I would give it a bash this morning on a day off. Eventually I found one calling at 353406, where a footpath goes under the railway line (not far from where we saw them on a guided birding walk a few years back). Other sightings; Sparrowhawk, Grey Wagtail, Dipper, and a beautiful and rather flirty pair of Goosanders below the gorge. What a muddy place!