The 400 kilovolt lines leave this substation in 3 different directions, linking this substation to similar substations near Weymouth, Plymouth and Taunton, and a couple smaller ones between.
One of the nearest power stations is the new one at Landgage in Plymouth, and Hinkley point in Somerset, and the 400 kilovolt lines bring the power to us from these power stations.
The substation has large transformers which reduce the voltage of the large power lines to 132 kilovolts which then leaves in the smaller pylons going to smaller local substations in Marsh Barton, Sowton, Exmouth, Cullompton, Newton Abbot and Ottery St. Mary.
When you arrive at ground zero you’ll hear a deep hum, that’s the sound of the 400 kilovattts of electricity coursing through the substations veins, the size and power of the substation is awesome.
It reminded my daughter of an animated film featuring a certain Giant made from Iron who tried to eat a place just like this, and there was a little boy who saved him.
You can park right at GZ and it shouldn’t take you to long to locate the log 
There is an additional hint should you need it.