 The North Somerset Levels are to the east of Weston @-@ super @-@ Mare , while the Axe valley is separated by the Isle of Wedmore from the Brue valley . The latter is separated by the Polden Hills from the main wetland of the Parrett / Tone / Cary valleys . The Poldens are a low narrow ridge of Blue Lias with alternating bands of limestone and clay . Because of the nature of the Levels and Moors , the Poldens have a significant visual impact . 
