Drysllwyn Castle stands on high ground overlooking the Tywi Valley with extensive views. It was built in about the 1220s by one of the princes of the kingdom of Deheubarth, and changed hands several times in the struggles between the Welsh and English over the ensuing centuries. It is considered one of the most important remaining structures built by a Welsh chieftain.
Drysllwyn was seized by Owain Glyndŵr in the summer of 1403 and when the English forces recaptured it they decommissioned it by blocking various access routes, walling up the gatehouse, removing the treads from stone stairs and even removing the hinges from the main gate. At some later stage, all the major buildings were burned to the ground. Following this a lot of the stone was removed from the site
The polygonal Inner Ward contains principal remains to the south west, with traces of the Middle and Outer Ward to the north east. The early thirteenth century curtain wall to the Inner Ward only stands 1m high. There is a garderobe to the east side, and a remodelled thirteenth century Gatehouse to the north east, surviving at foundation level only. On the south side of the Gatehouse is the Round Tower, the original keep. The foundations of the original Great Hall and Rhys ap Maredudd's hall survive.
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.