Portchester Castle is a medieval fortress in Hampshire. UK,

Portchester Castle is a medieval fortress that was developed within the walls of the Roman Saxon Shore fort of Portus Adurni at Portchester, to the east of Fareham in Hampshire.

The keep was probably built in the late 11th century as a baronial castle and Portchester was taken under royal control in 1154. The monarchy controlled the castle for several centuries and it was a favoured hunting lodge of King John. It was besieged and captured by the French in 1216 before permanently returning to English control shortly thereafter.

Thanks and credit to Google Earth Studio for this aerial video.