Castle Cliff Rocks is in effect the last formation of the Roaches, though we are many metres below the heights of the escarpment. A brief clamber on a few of these boulders is fun and will help you appreciate why the Roaches is a mecca for rock climbers. Please do take care here, however, especially in wet or icy weather.
This type of rock doesn’t crumble easily and offers a firm grip. Officially known as Roaches Grit, it is very hard sandstone. It formed from coarse sand washed down into a huge river delta during the late Carboniferous period, some 320 million years ago. This rock is a subdivision of the famous Millstone Grit found widely across the Peak District.
The stack here has survived because this is a particularly hard section of rock. It has withstood the eroding efforts of rain, ice and wind much better than the less durable material which must have once surrounded it.