Black Bull's base of operations is a headquarters that houses all of the members. The headquarters is in the form of a large house with asymmetric structures. The house consists of multiple stories with most of them made of stones and bricks. It has a large number of windows and chimneys and a single wooden gate for an entrance. The base is located in a forest within the Common Region.

Several features of the house are a dining hall where the members have their meals, a kitchen to complement the hall, a public bathing area, an underground cage filled with beasts, and a female living quarters which is heavily protected with traps. Regarding living quarters, it would seem to have been established that the senior members have larger quarters than the newer members.