The undulating landscape of this nature reserve is a patchwork of blanket bog, heath, grassland, meadows and woodland, which encompasses two hill farms - Geltsdale and Tarnhouse. It covers more than 19 square miles, rising from 200 metres above sea level to 620 metres. Spring and summer bring waders such as curlews and lapwings to nest, while male black grouse perform their lekking courtship rituals. Merlins, peregrines and short-eared owls hunt over the moorland, and hen harriers can even be seen swooping across the sky.