Archaeologists in Osaka, Japan, believe to have found clues about an non-existent Sanada Maru fortress built and used by warlord Sanada Nobushige during the Siege of Osaka (1614-1615). Sanada Maru was an Osaka Castle branch that projected southward from the "Sogamae" (general frame) moat, which defined the outermost contour of the Toyotomi clan’s castle. The