Haverfordwest Priory was a house of Augustinian Canons Regular on the banks of the Western Cleddau. The priory was first mentioned around 1200.
At the time of Henry VIII’s Dissolution of the Monasteries (1536–1541), it was acquired by Roger and Thomas Barlow, brothers of William Barlow, bishop of St David's.
From 1983 to 1996, the site (now under control of Cadw) was excavated and the outlines of the buildings are visible. Much architectural material of a high standard was discovered and can be seen in Haverfordwest museum. Also unearthed was a unique medieval garden with raised beds.
Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.