It is always worth revisiting unusual habitats, and the largest peat bog in Gwent is certainly worth repeated visits. I first looked at Waun Afon with Graham in the early 2000s, returned a few years later on my own, and then carried out an NVC survey of the bog over several days in ca. 2014. Last week I looked at the heathland along the south-western edge of the bog, NVC surveying the area between the peatland and the main track along the bog's western edge. This southern part falls in a different tetrad to the majority, so I took the opportunity to boost the total for SO20K from <50 to >100 bryophyte species. Highlights within the heathland area were a small patch of Bazzania trilobata, two boulders with Barbilophozia attenuata, one with B. floerkei, and a rather decrepit patch of Polytrichum strictum. A quick walk up the side of Cefn Coch to compare the heathland there with the area I had been surveying revealed increasingly abundant Rhytidiadelphus loreus and star find of the day: the first Sphagnum quinquefarium in VC35 for nearly 100 years! After completing the survey I wandered south to the ruin of Ty Rheinallt noting Archidium alternifolium and Riccia sorocarpa on a track and some remarkably high altitude (390m aOD) Syntrichia papillosa on an Elder. All in all, a worthwhile day.