The view is through trees west of East Cowes Castle, with what seems to be the northernmost of the two ponds marked on that side on early Ordnance Survey maps, apparently reflecting the light of a full moon rising beyond the rough skyline. The other pond may be shown in Tate D20825 (Turner Bequest CCXVII a 22).
This is among dozens of blue paper studies made in and around East Cowes Castle, presumably in the course of a single visit, including several showing the moon. For more on the various aspects of the house (demolished in about 1950), and its lost grounds as depicted by Turner, see the Introduction to this subsection.
Although not immediately apparent, losses were sustained in the 1928 Tate Gallery flood, when ink was offset to a sheet laid over this one during the recovery process (Tate D40523).
Blank; the heavily applied ink on the recto has bled through a little, and there is very slight ink offsetting, presumably from another drawing in this East Cowes sequence.