Lendo: A game of thrones, de George R. R. Martin
By the time Jon left the armory, it was almost midday. The sun had broken through the clouds. He turned his back on it and lifted his eyes to the Wall, blazing blue and crystalline in the sunlight. Even after all these weeks, the sight of it still gave him shivers. Centuries of windblown dirt had pocked and scoured it, covering it like a film, and if often seemed a pale grey, the color of an overcast sky… but when the sun caught it fair on a bright day, it shone, alive with light, a colossal blue-white cliff that filled up half the sky.