Japanese castle types, Yamajiro

Amongst the 3 types of Japanese castles (mountain castles - yamajiro, hilltop castles - hirayamajiro and flatland castles - hirajiro), the easiest to defend were the yamajiro. Taking advantage of the terrain, the fortifications surrounding the tenshu were also simpler to build, but unlike the hirajiro these were castles built only for military purposes, their location and size making them impractical for civilian use.

Although not one of the 12 castles in the original form, an interesting example and a good place to visit is the Gifu castle, located on Mount Kinka at a height of 300 meters over the surrounding area. There are many interesting artifacts on display (especially related to the famous Oda Nobunaga) and the 360-degree view from the top of the castle is wonderful.
The steep climb takes about one hour by foot, but there's also a ropeway that will take you there in just 3 minutes...