This stamp was on a birthday cardI received (not from Wales but from a friend who lives in Middlesex!). Apparently it's one of a collection issued by the Royal Mail of iconic places around the UK. See www.bbc.co.uk/news/uk-wales-north-west-wales-17665923
To answer Jack's question, 1st just applies to it being a first class stamp.
This stamp was on a birthday cardI received (not from Wales but from a friend who lives in Middlesex!). Apparently it's one of a collection issued by the Royal Mail of iconic places around the UK. See www.bbc.co.uk/news/uk-wales-north-west-wales-17665923