Well spotted Gwynant, it is Ynys Y Fydlyn. We had a coastal walk from Church Bay ( Porth Swtan ) to Ynys Y Fydlyn and then returned via some country lanes.

Hope that your hip operation is continuing to improve and I forgot to mention about two friends I know who had the op. One was a lady of 71 who was able to play badminton again after a couple of months. The other was the son in law of a guy that I used to go walking with and the son in law who had had two hip replacements and this guy both walked up Kilimanjaro together.

Yorkie, Ynys = Island

but it's a bit like Llanddwyn Island and is only an island on certain high tides