Barkbooth Lot, situated near the head of the Winster Valley in the south-eastern Lake District, covers 27 ha of wonderfully diverse habitat, with two small tarns nestled amongst undulating fell grassland, rocky outcrops, bracken and scrub with a backdrop of oak woodland.

This wonderful little Nature Reserve, bequeathed to the Cumbria Wildlife Trust in 1975 by Mrs Sheila Caldwell, is a haven for both terrestrial and aquatic wildlife.

Barkbooth tarn is an outstanding example of a clean water pond of high ecological value, and is notable for its rich invertebrate fauna including populations of rare and enigmatic Medicinal Leech Hirudo medicinalis and Pond Mud Snail Omphiscola glabra. It is also home to an array of dragonfly and damselfly species including Black Darter Sympetrum danae , Emerald Damselfly Lestes sponsa, Large Red Damselfly Pyrrhosoma nymphula and Common Hawker Aeshna juncea as well as a diverse mix of both submerged and emergent aquatic plants.

The tarn is in excellent condition due to the current management regime which includes access by grazing livestock, which is particularly important to Medicinal Leech as mammalian blood is of much higher nutritional value than amphibian blood. Grazing also helps to maintain the marginal sedge beds and Sphagnum lawns which are also important for both Medicinal Leech (e.g. for egg-laying) and Pond Mud Snail, by slowing the development of tall, dense emergent vegetation which could take over large parts of the tarn.