Afon Tryweryn is a river located in Wales, flowing through the picturesque landscape of Snowdonia National Park. It is approximately 20 kilometers long and is known for its scenic beauty and diverse wildlife. The river is a popular destination for outdoor activities such as kayaking and fishing. The river's source is near the village of Tryweryn, and it eventually joins the River Dee. Afon Tryweryn is also significant for its historical context, as the valley was flooded in the 1960s to create a reservoir for the city of Liverpool, leading to the submergence of several villages.