The river Conwy starts its journey from a small lake high up on an isolated moor. The valley proper begins at the Conwy Falls situated above the confluence with the river Lledr close to Betws-y-Coed, the starting point for many forest and lake walks. Nearby Dolwyddelan has the ruins of a Welsh castle (as opposed to the 'English' castles of Edward I). Penmachno has a woollen mill and the National Trust house at Ty Mawr, the home of Bishop Morgan first translator of the Bible into Welsh.

The picturesque river leads to the eastern gateway of Snowdonia (Betws y Coed) and is joined by several tributaries creating a series of waterfalls before emerging from narrow, steep sided mountain valleys into the more tranquil agricultural Conwy Vale, to the market town of Llanrwst. Here, originally the only bridging point across the river, is the often photographed Inigo Jones bridge.

The river flows on, passing the villages of Trefriw, with Roman spa and woollen mill, and Rowen to the west and Eglwysbach to the east before flowing under Conwy bridge and out into the Irish Sea.