View this artwork by appointment, at Tate Britain's Prints and Drawings Rooms
Made with the page turned horizontally, this and the sketch on folio 90 recto opposite (D02129) presumably show the same building, though the ruins in each case differ somewhat in scale and extent. Finberg suggested that this might be Dolbadarn Castle,1 but the identification does not seem plausible for either.
A somewhat more likely identification is Dolwyddelan Castle, a thirteenth century fortification on a bleak ridge above the Conwy Valley. Its keep was substantially restored in the nineteenth century, but it was a remote and atmospheric ruin when Turner saw it in 1799, having associations with Llywelyn ap Gruffydd, a prominent opponent of Edward I in his campaigns to subdue Wales, the theme of Turner’s ‘War’ and ‘Peace’ watercolours of 1799–1800 (Tate D04164,2 D04168; Turner Bequest LXX M, Q).