Considering the time it was built, the castle had great architectural achievement. “Firstly, the exterior is filled with moats and stone walls that are symbols of the solid defenses in the Osaka Castle.”("Osaka Castle"). The moats are around 80 meters in width and the walls are about 20 meters in height. These walls created with granite stretch 7.5 miles!
“The solid base, although of modest height, lays in the midst of a bewildering maze of rivers, reed beds, and ever changing islands that made up the estuary of the Kiso River where it entered Osaka Bay. This topography, the classic hirajiro situation, was cleverly exploited in the construction of Osaka. Concentric rings of huge stone walls build around earth cored provided multiple layers of defense with little height advantage until one moved closer to the central keep, which was of such a size as to dominate its surroundings completely. Osaka’s keep was therefore an example of a structure that lay right at the heart of a complex defensive arrangement”(Turnbull 143).
This castle has so many defensive structures, including gates, turrets, and citadels, which made it able to survive though many wars. Back in medieval times, the lord would have felt very safe within these castle walls due to just the abundance of protection it brought.