Town Kelloe Bank has a unique and very distinctive landscape with diverse flora and fauna.
It was shaped by the last ice age and is located within what remains of a glacial lake meltwater channel system. The steep sides of the winding valley are primary magnesian limestone grassland.
Blue moor and quaking grass, glaucous sedge and meadow oat-grass flourish on the thin soils of the valley sides. Fragrant orchids and classic magnesian limestone herbs such as wild thyme, salad burnet, milkwort, and autumn gentian also thrive.Large amounts of common rockrose provide food for the larvae of the northern brown argus butterfly. Other butterflies include common blue and small copper.
Managed areas of hawthorn, bramble, blackthorn and gorse scrub alongside ash woodland enhance the wildlife interest. North facing slopes, with wet flushes, support butterwort and the largest population of birds-eye primrose found in County Durham. Due to the sensitivity of the magnesian limestone grassland, visitors are asked to restrict access to the valley floor and not climb over the fences onto the slopes.