Hopton Castle or Tower stands about half a mile south of the parish church. It occupies a knoll or patch of gravel, which rises out of a marshy bottom, caused by the waters of the brooks which here fall into the main stream. There is a central mound, low but well defined, which is surrounded by a circular ditch, and beyond this ditch are the traces of two or three platforms, but slightly elevated, and which have been fortified by ditches fed with water by a streamlet from the west. No doubt the place was occupied by some tenant of Edric, for its earthworks are certainly pre-Norman, and perhaps of the tenth century. It is probable that its Norman tenant and his descendants, who derive their names from the place, were for some centuries content with such defences as they found ready to their hands, for there is no trace of masonry, either of the eleventh or twelfth centuries. The castle consists of a single tower, quadrangular, 48 feet by 50 feet, with walls 10 feet thick. It stands upon the mound, which is not above 6 feet high, and through which the foundations are no doubt carried. It has a basement at the ground level, a first or main floor, and an attic in the roof. The exterior is plain, having a double-scroll stringcourse from 4 feet to 6 feet from the ground. Each angle is capped by a pair of broad pilasters of slight projection, which ascend to the summit, and probably carried four square turrets. The doorway is on the north side, not far from its west end, and nearly at the ground-floor level, ascended from the exterior by three or four steps. The south front has a square projection at its west end, in which is a garderobe. The doorway, the only entrance, is 6 feet wide, and has an equilateral arched head. Its mouldings are two convex quarter circles divided by a step. Their character is plain but excellent Decorated. Over the doorway was a triangular hood, now broken away. There is no portcullis, only a strong door.