It is a large, old building located on northern end of Miyama, and a Japanese-style building with a classical elegance befitting the area. Even within the old style of Miyama, it is of a rare style, and it can be considered a rare example of architectural history. Though it was large and previously unused, its history made it so it was never torn down even in its degradation and having taken up a large amount of space in an area of civic planning.
It has a very old storehouse built on the edge of the yard, which utilizes a key cast in an ancient style far different from the modern cylindrical kind utilized in the rest of the estate. The door is old and rusty, constantly creaking as it opens. While the rest of the house is unsuited to be a magus' workshop, the storehouse is suitable enough for a makeshift area for magi to work. The house is too open, letting prana flow about freely, so the closed nature is suitable as long as a magic circle can be established. Irisviel von Einzbern utilized it in the Fourth Grail War, leaving the Magic Circle that is later used to summon Saber, and Shirou utilizes it for his daily meditation and practice. He stores broken appliances and failures in projection magecraft. He has a special love for it, and often spends time fixing items within.
It was bought for the purpose of being used as the Einzbern headquarters in the Fourth Holy Grail War after the Einzbern Castle was damaged to the point could no longer be utilized. Its close proximity to the Tohsaka and Matou residences, while dangerous, was thought to be the safest choice due to the unpredictability of the choice. It had been unused for a long period of time, but still showed signs of renovation. The yard was unkempt at the time, and the interior was full of dust. Kiritsugu continued to occupy it with his adopted son after the Holy Grail War, and Shirou, with help from Raiga Fujimura, managed it after his death.