BORROWDALE VOLCANICS

What is it? A group of igneous rocks formed from lavas, ash and rock fragments fired out during massive volcanic explosions roughly 450 million years ago. These now make up some of the highest and most iconic hills in the Lakes, including Scafell Pike, Great Gable and Helvellyn.

Where? In the central Lake District around, unsurprisingly, Borrowdale, but also Cross Fell and Teesdale.

How slippy? Mixed – it depends on the rock. Most is fine-grained and fairly generic. Neither particularly slippy or grippy.

And another thing It is the hardness of this rock that gives the National Park its peaks and lakes, by resisting erosion and preventing water from draining away.