This was the scene from my kitchen window one October morning in 2014 as dawn was breaking over the ridge of Mynydd Carn-y-Cefn. These trails are mostly the work of airliners homing in on Heathrow 180 miles to the west. I suppose it's lucky that blue-sky mornings are pretty rare here! The thin black line is the phone line that delivers this website to you. The illusion that it goes straight to the top of the mountain is nice but it in reality it goes no further than a pole at the bottom of my garden. See
my rant about con trails at W14/1