sentences:  There is a hidden couloir in the Vanoise National Park, also unofficially known as the Rum Doodle, and named by one of the first to discover and ski down it, Will Eaton.So-called as it took a long time to find the entrance, and skiing down it wasn't without complications.The number "153" that appears numerous times in the book is the number of the house on Borough Road, Middlesbrough where the Bowman family moved shortly after Bowman's birth in 1911.