DID YOU KNOW?

Britain’s largest hydro scheme is inside a mountain in Snowdonia. Llyn Marchlyn Mawr lies high on the slopes of Elidir Fawr and when demand for power surges – say at the end of a popular TV show when we all put the kettle on – water is released through tunnels and caverns inside the mountain, powering turbines on its way to the lower lake of Llyn Peris. Find a route guide for the Electric Mountain at walk1000miles. co.uk/bonusroutes