So some interesting finds for anyone who is interested. A roundhouse was found under Bamburgh Castle, a site which has been used by humans for a long time, it became the seat of the Northumbrian Kings till the Kingdom became Northern Northumbria and Southern Northumbria(Jorvik.)
The site of the castle was called Dun Guaydri when the Anglo-Saxons arrived. The castle was also homed to William Armstrong who had the first house in the world to use hydroelectric power which he invented but also lived in the Castle and became first castle in the world to fall to gunpowder.
https://www.bamburghcastle.com/bamburgh-castle-excavations-unearth-unique-romano-british-roundhouse/