I know this won't appeal to the masses - it's not your typical wallpaper. But someone did comment in one of my previous submissions that I should also take photos of 'less pretty' things. How about some ugly railway tracks?
Nature uploaded by Fidan Sukur on We Heart It
The peacefullest times I remember were as a kid laying down drowsily in the backseat of the family van at night on road trips while my dad drove, and mom slept in the passenger seat. I've never known a greater sense of safety since those times.