The River Dee by Theo Tyszkiewicz. The source. The River Dee’s source is on the slopes of Dduallt above Llanuwchllyn in the mountains of Snowdonia [in Wales.]. The course of the River D ee. Towns and cities along the River Dee. The River Dee is 110 km long.
The Dee Estuary is one of the UK’s premier birding locations for wetland and shorebirds such as Shelduck, Wigeon, Teal, Pintail, Oystercatcher, Grey Plover, Knot, Dunlin, Black-tailed Godwit, Curlew and Redshank.