Watendlath is owned by the National Trust and sits high between the Borrowdale and Thirlmere valleys at 863 feet above sea level. Watendlath Tarn is fed by Bleatarn Gill from Blea Tarn, 700 feet above, below Bell Crags. Water from Watendlath Tarn flows into the beck of the same name and eventually feeds Lodore Falls, and ends up in Derwent Water.