Thirlmere is 3.5 miles long, 0.11 mile wide and 131 feet deep.
Did you know?
Thirlmere was originally two smaller lakes. Manchester City Corporation Waterworks bought the lakes in 1889 and built a dam to create the single large reservoir now known as Thirlmere. During the creation of Thirlmere, settlements of Armboth and Wythburn were submerged.
Walkers might be interested to know that Helvellyn ridge lies to the East of Thirlmere.