The site is a kettle hole, a deep pond formed in the void remaining after a submerged glacial calf block melted.

[1][2] Barelees Pond is situated in the north-east of England, immediately south of the Anglo-Scottish border in the county of Northumberland, some 0.95 miles (1.53 km) south-east of the town of Cornhill-on-Tweed.

[1][2] Within the perimeter of the island is a carr woodland - in part a quaking bog floating on the pond - supporting birch (Betula sp.)

The distinct stable central areas of the island supports Scot's pine (Pinus sylvestris) and a ground flora of ling (Calluna vulgaris) and cross-leaved heath (Erica tetralix).

The perimeter bank supports elder (Sambucus nigra), hawthorn (Crataegus monogyna), wild rose (Rosa sp.