 The work was carried out between 1245 and 1270, and included the construction of a towered curtain wall, a gatehouse of considerable size with two large towers, two smaller gatehouses, a small watergate, a small gateway into the city, a chapel, and a new stone keep, first known as the King's, later Clifford's, Tower.Clifford's Tower is of an unusual design.The two-storey tower has a quatrefoil plan with four circular lobes.