www.ukbutterflies.co.uk

Whilst walking by Pennard Castle on the Gower the other day, I came across this decent-sized, stonecrop-like plant growing on the castle wall. Anyone any idea of the species?

I think it is Navelwort (Umbilicus rupestris) David... Note the dimple (navel) in the centre of leaves where it attaches to stem underneath.

Yes, that looks to be it, Trevor. Many thanks for your help.