The jagged sweep of young fold mountains is bewildering&mdashfrom the edge of the Karakoram in the northwest, to the verdant hills of the Northeast and beyond, until finally dissolving into the lush paddy fields of Myanmar the Himalaya has nurtured a staggering array of societies over millennia. Much of it has been shaped by the splendid isolation of these cultures, before the network of roads delivered modernity to the remote hill towns nestled high up in the clouds.