sentences:  The area was originally part of the Llansillin Rural District of Denbighshire and was made up of the civil parishes of Llanarmon Dyffryn Ceiriog and Llangadwaladr.In 1935, these parishes were transferred to the new Ceiriog Rural District.The Local Government Act 1972 abolished all of these administrative structures, replacing them with the new Community of Ceiriog Ucha, part of the Glyndŵr district of Clwyd.