Penmon Priory on the Isle of Anglesey. A walk Around the Ruins with some History.
Penmon Priory is believed to have been established by St. Seiriol, as early as the 6th century. The existing 12th century stone St. Seiriol church and tower date from around 1140 and is a fine example of Romanesque architecture.
Within the church (that was closed) interior there are two medieval crosses carved in the Celtic style. Close by the church is a stonebuilt dovecot (c.1600s) built by the Bulkeley family of Beaumaris. St. Seiriol's Well also lies close to the church and is believed to have healing powers and visited by pilgrims.
A little info on the Flagstaff Quarry - https://coflein.gov.uk/en/site/40625/details/flagstaff-quarry-general#:~:text=Site%20Description%20Flagstaff%20Quarry%20is,altered%20circa%201885%20to%201916.