Lanty’s Tarn sits at the end of the ridge between the Grisedale and Glenridding valleys. It’s a natural tarn that has been enlarged with a concrete dam wall to provide a water supply to Patterdale Hall. There is some debate as to how the tarn was formed. One opinion is that the hollow which it occupies is the result of glacial meltwater channeling. Others say that it was scooped out by a tongue of ice between the Grisedale and Glenridding glaciers. There are certainly roches mountonnees carved smooth by the flow of the ice on Keldas, the knoll to the east of the tarn. But that doesn’t exclude the meltwater theory.
Nearby is an ice house where ice from the tarn was stored underground by Patterdale Hall for use long into the summer.
But who was Lanty? One theory is that he was Lancelot Dobson one time owner of the estate. Lanty being a diminutive name for Lancelot.