A note on the back of this photo states "possibly Pilgrim's Church", which is the ruined St Michael's Church near Trefenty Farm, St Clears. It is a listed building originally dating from the 12th century. By the middle of the 19th century it had fallen into disrepair and was replaced by the new church on the A40 near the present Forge Restaurant.
Further details of its history can be found on the Coflein website:
https://coflein.gov.uk/en/site/102138/?term=Abercywyn%20%20church