Published on Sunday, April 7, 2013 by Kathy McCabe The Italy Mix is a post about the most interesting Italy and Italy travel news and human interest stories around the Web each week. Here are our top picks for this week: To Siena to See the Door to Heaven: For the first time ever, the upper walkways  in the vault of of  Siena's Duomo are open to visitors. (Tuscan Traveler) Mantua: Italy's Sleeping Beauty City:...