Grey Abbey is a ruined Cistercian priory in the village of Greyabbey. It was founded in 1193, by John de Courcy's wife, Affreca (daughter of Godred Olafsson, King of the Isles), as a daughter house of Holmcultram Abbey in Cumbria. It had declined by the late Middle Ages and was dissolved in 1541. It was burnt out by Brian O'Neill in 1572. It was granted to Sir Hugh Montgomery who re-roofed the abbey in 1626 and refurbished it for use as a parish church. It was used until 1778.
The remains consist of a church with cloister and surrounding buildings to the south. Entry is through an elaborate west door, into an aisleless nave, transepts with two chapels in each and a short chancel with tall lancet windows. The buildings around the cloister include an aisled chapter house and a refectory with reader's pulpit, although the west range and cloister walks have disappeared. Three buttresses on the south wall of the nave are part of a conservation programme carried out early in the 20th century. In the north wall of the choir is an effigy tomb which may be that of Affreca, while an armoured knight figure in the north transept may represent John de Courcy. There are also monuments dedicated to the Montgomery family from the 17th and 18th centuries.
References: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.