Our Membership Secretary, Richard E Huws, has kindly allowed us to include a fascinating study of his (in Welsh) of Welsh place-names containing the element dwrgi / dyfrgi (otter). He would like to be informed of other similar names, if there are any. This has now been updated.

https://www.cymdeithasenwaulleoedd.cymru/wp-content/uploads/2021/02/DWRGI2.pdf