River Thaw

River Thaw
The River Thaw south of Cowbridge
Native nameAfon Ddawan (Welsh)
Location
CountryUnited Kingdom, Wales
RegionSouth Wales
CountyVale of Glamorgan
CitiesCowbridge, Llanblethian, Aberthaw
Physical characteristics
Source 
  locationSouthwest of Llanharry, Vale of Glamorgan, Vale of Glamorgan, Wales
  coordinates51°30′30″N 3°27′03″W / 51.5082°N 3.4509°W / 51.5082; -3.4509
Mouth 
  location
Bristol Channel
  coordinates
51°22′58″N 3°23′46″W / 51.3828°N 3.3961°W / 51.3828; -3.3961
Length20.0 km (12.4 mi)
Discharge 
  locationBreaksea Point, Vale of Glamorgan
Basin features
Tributaries 
  leftKenson River, Nant Tre-gof, Nant Aberthin
  rightNant y Stepsau, Factory Brook

The River Thaw (Welsh: Afon Ddawan) (also Ddaw) is a river in the Vale of Glamorgan, south Wales. At 20 kilometres/12.4 miles, it is the longest river entirely in the Vale of Glamorgan.