 The name comes from Thomas Dawe, who owned "castell" field in 1537.The fort is situated on an east-west cliff about above the sea, on a tapering spur of land bounded by the Washford River to the south, as it flows to the sea at Watchet, about 1 km east.The ramparts of the fort would have formed a semicircle backing on to the sheer cliffs, but coastal erosion has reduced the size of the enclosure, and later destruction by farming, limekilns, and the B3191 road, have left only about of ramparts visible today.