Okayama Castle and the Asahi river

During the medieval period, one of the main things to consider when deciding the construction of a castle was the location. And in some cases, the surrounding landscape was modified to enhance the castle's defensive capabilities.

One such case was the Okayama Castle, which was built on a small hill nearby the Asahi river. At the time of its construction, the builders altered the river's course, making it flow along the eastern side of the castle walls.