A short visit at 52 mins, plus a bat colony at 42 min, followed by Llangattock:
https://www.bbc.co.uk/iplayer/episode/b07g6zpk/the-brecon-beacons-with-iolo-williams-series-1-reversions-episode-2
This is a repeat of clip mentioned here, but now part 2 rather than 4 (OFD is at 23 min in current part 1):
https://ukcaving.com/board/index.php?topic=19829.0
