Mother Cap is a very large boulder which sits in a prominent position about 500m north of the Surprise View car park near Hathersage.
Despite how the image appears, it was taken at midnight by the light of the full moon. It was fully dark and the cloudy sky helped to mask much of the moonlight, but a 16 second exposure at f/4.5 and ISO1600 captured enough light to be properly exposed.
The warm orange above the horizon to the right of the rock is the glow of Sheffield's city lights. In the full-sized image you can clearly see stars in the areas of blue sky.