Vale Of Clwyd
History
Dyffryn Clwyd was a cantref of Medieval Wales, and from 1282 was a marcher lordship.
Settlement and administration
At its seaward end are the coastal resorts of Kinmel Bay (Welsh: Bae Cinmel), Rhyl and Prestatyn whilst the town of Abergele and city of St Asaph (Welsh: Llanelwy) lie just inland. The other principal towns of the vale are Denbigh (Welsh: Dinbych) and Ruthin (Welsh: Rhuthun), also Rhuddlan. Most of the area falls within the modern administrative county (and unitary authority) of Denbighshire and a portion is in Conwy County Borough; much of it lies within the Vale of Clwyd UK Parliamentary constituency.
Geology
The Vale of Clwyd is a sedimentary basin which takes the form of a half-graben whose eastern margin is marked by the Vale of Clwyd Fault. Like the Cheshire Basin further to its east, it is mostly floored by thick deposits of Permian and Triassic sandstone. Around St Asaph, late Carboniferous, Coal Measures mudstones and sandstones occur. The area was overrun by ice during the ice ages whose legacy is a covering of glacial till across the area and a swarm of drumlins along the western edge of the vale. Alluvium is encountered across the floodplains of the River Clwyd and its tributaries.