The structure of the lodge, named after nearby Mount Asama, made it a stronghold: it was a three-story wood and concrete edifice built into the side of the hill atop an exposed base of steel-reinforced concrete. The upper floor was slightly larger than the two below, giving the lodge a mushroom appearance. The lodge towered over the steep, snow-covered slopes below and its windows had heavy outer storm shutters. The building's maze-like floor plan and narrow staircases made it easy for the defenders to block off movement inside. The radicals would spend most of their time on the uppermost floor, which contained a kitchen, dining room, tatami-mat sleeping room, and a commanding view of the surrounding valley and hills. The radicals placed large pieces of furniture and futon bedding around the doors and windows and secured them in place with wire.