page_title: Malltraeth Marsh
section_title: Geography
hierarchical_section_title: Malltraeth Marsh / Geography
caption_attribution_description: English: Pool alongside the railway line on the Malltraeth Marsh
context_page_description: Malltraeth Marsh is a large marsh area in Anglesey, North Wales, located north east of Malltraeth village, along the flatlands of Trefdraeth Bodorgan, Llangristiolus and south of Cefn Cwmwd.Rhostrehwfa. It is reclaimed from estuarine marshes after the construction of the Malltraeth Cob, a 1 mile long embankment, and the subsequent canalisation in 1824 of the Afon Cefni.
  The name Malltraeth comes from Mall, and Traeth. The marsh measures 1,366.5 hectares in area. The area is recognized as a Site of Special Scientific Interest, and has a range of reedbeds, marshes, wet grassland and small pools/lakes.
context_section_description: Located in the cwmwd of Malltraeth,  Cors Malltraeth Marsh is situated on the western side of the Afon Cefni valley which crosses Anglesey parallel to the Menai Straits, approximately 4 miles (6.4 km) to the northwest. The habitat of Cors Ddyga on the eastern side of Afon Cefni has been reverted to wetlands and reeds. The wetland reserve is officially called RSPB Cors Ddyga.  It consists of marshy grasslands, lakes, pools, fossiliferous coal and shales.
  Both marshes- Cors Malltraeth and Cors Ddyga geology is characterized by carboniferous limestone, millstone grit, soft coal-measure shales, sandstone, beds of coal, and Permian strata. The Afon Cefni valley is 9 miles (14 km) long and runs almost exactly parallel to the valley of the Menai Straits.  Many years ago, at its north-eastern end, deep glacial striatums on the Millstone Grit ran straight down the shallow valley towards Caernarfon Bay.
  Malltraeth Marsh is a wide and perfectly flat expanse of reedy pasture. On its far side, there is an embanked tidal river that opens to Malltraeth Sands, 0.5 miles (0.80 km) to the south. A short tunnel—the first one in Anglesey—pierces the low hills which extend along the west side of Malltraeth Marsh before reaching Bodorgan railway station. Above Malltraeth lies the extensive Common of the marsh, which is bounded on the northwest by the parishes of Llangadwaladr, Trefdraeth, and Llangristiolus; on the northeast by Llangefni and Llanffinan. Cors Ddyga (Tygai's Marsh) lies in the commote of Rhosyr . It is situated on the eastern side of the Afon Cefni River or Afon Fawr Llanfihangel-y-Ceifiog, Llanidan, Llangaffo, Llangeinwen, and Newborough.
caption: Pool alongside the railway line on the Malltraeth Marsh
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