These coal-holds are also called porcupines, because of the iron hooks you can see on the roof. In wartime they could hide them by putting camouflage cloths all around them.
Young soldiers, waiting for the enemy to come. One awake and alert, one asleep. You get very tired of fighting wars. Most of the time it is not your war. It reminds me of the child soldiers in Africa. What they experience is too cruel.
But here we have no war and talented artists can spray graffitichildsoldiers on a concrete building that has become an anachronism in the landscape. It is good to be free and create.