Afon Merddwr

Afon Merddwr
Afon Merddwr at Pentrefoelas
Location of the mouth within Conwy
EtymologyWelsh for stagnant water
Location
CountryWales
CountiesGwynedd
Physical characteristics
Source 
  locationMwdwl-eithin
  coordinates53°03′40″N 3°37′16″W / 53.061°N 3.621°W / 53.061; -3.621
Mouth 
  location
River Conwy
  coordinates
53°02′42″N 3°42′25″W / 53.045°N 3.707°W / 53.045; -3.707
Length16 km (9.9 mi)

Afon Merddwr is a river in the south of the county of Conwy, Wales. It is a tributary of the River Conwy and joins it near Pentrefoelas. It is about 10 km long. "Merddwr" is Welsh for backwater or stagnant water, suggesting that it was named for its current or water quality.