The hall of the Five-Hundred (Cinquecento) at Palazzo Vecchio; Florence;Italy.Italian art expert Mauricio Seracini says he is on the verge of discovering a long-lost Leonardo da Vinci masterpiece ' The Battle of Anghiari ' hidden in a secret cavity behind a wall of the Palazzo Vecchio in Florence; Italy. October 30;2009. Palazzo Vecchio's grand ceremonial chamber; the Hall of 500. At right : Vasari's fresco 'The Battle of Marciano'. Leonardo's 'The Battle of Anghiari' should be hidden behind . Photo: Eric Vandeville/akg-images