The platform, covered by the base-court, is an irregular figure, governed by the ground, rounded to the east, and presenting right angles to the north and south-west. Its dimensions are about 80 yards east and west, by 35 yards north and south. There is a large drum-tower at the south-west angle, and another, with a square rear, in the centre of the south front, and there are traces as of a third capping the south-east angle. These towers are 18 feet diameter, have a basement, a first and second floor, and are about 23 feet high above the court, and 35 feet to the field. In the west front, close to the angle-tower, is a gateway; an opening in a very thick low curtain, round-headed, and probably of the date of the tower. It had a drawbridge and portcullis, and may have had a low upper story. Above the door, outside, is a flat entablature, with mouldings in the Renaissance style, and the adjacent bastion and curtain are pierced with long loops, placed horizontally, evidently intended for musquetoons, and therefore insertions. They are similar to those in the north-east bastion of Berwick town wall. The southern bastion has the original vertical loops for bows and arrows. The west is the weak side, for which nature has done nothing. The curtain accordingly is on that side thickened to 12 feet or 15 feet, and there may have been a ditch, now filled up. The court was divided by a cross wall, north and south, of no great strength, and the tower stood in the western half, from six to eight yards from the three outer walls. The northern curtain is an irregular heap of ruins; upon it, opposite to the tower door, there seems to have been a mass of masonry ascended probably by steps, and serving as an abutment to the stone arch by which the main or first-floor entrance was reached.