National Grid is currently consulting on the proposed route for NWCC from now until 6th January 2017.  You can find detailed maps of the route here at National Grid's website.

Below is an overview map of the entire route taken from National Grid's Project Information Overview document.

The route takes the cables underground through the National Park to protect the landscape, but as soon as the line is outside of the Lake District, it reverts to pylons and overhead lines up the Whicham Valley and around the head of the Duddon Estuary.  For 20km, there will be negative impact on the National Park which National Grid is not proposing to mitigate to prevent damage to the landscape.