Leonardo da Vinci, in a Renaissance version of Mad Magazine, may have painted his famous Mona Lisa in a number of ways, including nude. Now, a painting has surfaced that looks much like the original, sparking debate over just how far the master took his iconic painting. The newly revealed painting, hidden for almost a century within the wood wall of a private library, shows a portrait of a half-naked woman with clear links to the famous (and clothed) Mona Lisa. The work, which documents suggest was at least based on never-seen similar work by da Vinci, is now on...
