A building with complex plan and monumental structure of stone blocks. The building is north- south oriented with its long axis and with sizes 22X 17 m. The ground floor is divided in three sections each divided in several rooms. The official entrance is on the north and it introduces to the central part of the building. The side parts consists of three rooms, the middle 11 m. long and the end rooms are smaller of almost square plan. Round brick columns for winding stairs are built in the western smaller rooms. The building is connected to the Palace church on the east by two lines of columns which bore a covered gallery. Cornice parts were found during the research which are part of the architectural decoration. The flooring is made of marble plates.