In the upper part of the entrance wall that forms a triangle it is possible to identify some big and small boats sailing in a sea scattered with creatures. The big boat on the left has sails with black stripes, and dark-haired sailors or travellers. In recent years the meaning of this representation has been much debated. Some have argued that the ships evoke the times of the Crusades and perhaps represent the pilgrimages to the Holy Land. Others have even spoken of a celebration of the siege of Antioch in 1908, during which the lance of St. Longinus was found, a saint who had died in the city in the first century AD. Arturo Calzona, on the other hand, believes that it is the representation of a river siege, carried out by the people of Mantua to conquer the fortress of Ripalta (Rivalta) on the River Mincio in 1114.