Floors of the Great Keep
The Great Keep is a six-story wooden structure that functioned as a lookout tower, storehouse, and final bastion during a siege. It reaches a height of 29.4 meters and is believed to have been completed in 1594, along with the Northwest Tower and Roofed Passage.
First Floor
The first floor consists of a central platform surrounded by wide corridors where defenders could gather. Small holes in the pillars indicate that sliding partitions once divided the central platform into four rooms that may have been used to store rations, gunpowder, and weapons.
Second Floor
Although the second floor is similar in size and function to the first floor, its latticed windows provided defenders with broader lines of sight by which to fire down at enemy forces. Small holes in the pillars indicate that there were as many as eight rooms, which could have been used as storage space or for quartering troops in times of emergency. This floor now houses the Matsumoto Castle Firearm Museum.
Third Floor
The third floor is also known as the “dark floor” (kurayamijū), because the only source of natural light is a single, latticed dormer gable. Structurally, the third floor is hidden behind the hipped-roof eaves that project from the top of the second floor, making the inclusion of windows impossible.
The exact use of this floor is unknown. There is an opening in one corner of the ceiling that connects to the fourth floor, and it is thought that it may have been used for hauling supplies from the third floor to the fourth.
Fourth Floor
On the fourth floor and above, the castle’s interior changes considerably. The ceilings are higher, there are more windows, and the pillars have all been planed smooth. Unlike on the lower floors, there are no small holes in the pillars here, but the open space is believed to have been divided into three rooms using curtains or folding screens.
The largest partition on the fourth floor is a sitting room for the daimyo, which he would have occupied during a siege. This room is separated from the rest of the floor by thin bamboo blinds, which indicate the high status of its intended occupant.
Fifth Floor
The fifth floor would likely have been used as a planning room in the event of an attack. The floor’s wide, latticed windows face in each of the four cardinal directions, making it possible to monitor the area in and around the castle compound while safely behind cover.
One pillar located on the northern side has rope marks worn into it. These marks are said to have been made sometime between 1903 and 1913, when the pillar was used as an anchor point to adjust the Great Keep after it had begun to lean to one side.
Sixth Floor
The sixth floor would have been used as a headquarters for the daimyo in times of emergency. Its windows look over the surrounding landscape all the way to the mountains in the distance.
During repairs in the 1950s, it was discovered the sixth floor may originally have been designed as a smaller interior space surrounded by an outer veranda. Ultimately, the interior was expanded to include the entire sixth floor. This decision was likely made to account for Matsumoto’s harsh winters and to prevent rainwater from seeping in and damaging the lower floors.
