They just built castles that were most effective for them at the time given the resources at hand and the purpose of the castle being built. No one said “let’s build X type castle here”. For the sengoku builders, they had smaller territories and had to work with what was at hand, the best most suitable high ground more often than not. Early Sengoku castle battles were more about who could outlast the other longer. Build a castle that’s difficult to attack and wait out the siege, which will last until planting or harvesting season begins and all the attacking warriors trickle back to their farms. The “castle” was just a place you fled to in times of siege, thus higher ground, and not a year round base of operations. It was Nobunaga-Hideyoshi who started changing this by employing a larger professional warrior class that could attack a castle in the off season or through the seasons. As territories grew and warring became year round, more practical bases on smaller mountains or somewhat down the mountains were more frequently used. These are easier to attack than higher mountains so we build up the fortifications, stonework, bigger walls/gates, and so forth. Again, we’re talking about a spectrum of castle types and the needs and area also dictate the type of castle.
If you look at Nobunaga’s main bases they go from Kiyosu (very flat) -> Komaki (small mountain) -> Gifu (huge mountain) -> Azuchi (medium mountain). Then if you look to the Late Hojo, whose base is at Odawara, Odawara Castle itself is fairly flat with the tenshu sitting on a small hillock. Good place for living and administering, but the entire border of their lands is a string of high mountaintop castles that form a defensive perimeter.
|English Name||Matsukura Castle|
|Castle Condition||Ruins only|
|Historical Period||Pre Edo Period|
|Features||trenches, stone walls|
|Location||, Gifu Prefecture|
|Coordinates||36° 7' 34", 137° 14' 2"|
|Year Visited||Viewer Contributed|