The greater number of the buildings which formerly surrounded the church are either destroyed, or so altered by Turkish minarets and buttresses that it is difficult to conjecture their original form.[239] On the north and south of the narthex are long porches of Byzantine workmanship, with cylindrical vaults. In the northern one is a flight of fourteen steps leading down from outside to the narthex. The southern porch is called by Von Hammer the Vestibule of the Warriors. It is mentioned by Nicetas as the place where the Archangel Michael was represented in mosaic. It was through this porch that the emperor passed to the church, and here some of the bodyguard would remain. The vaulting still bears the remains of mosaics which are now covered up. On the east sides of both the northern and southern porches are accesses to the gynaeceum, formed of a series of inclined planes. The entrance to the northern one is from the porch, but the southern stair is reached from a narrow passage between it and the baptistery. To the west of the northern and southern porches, in the angles between them and the outside walls of the atrium, are the two minarets built by Murad III. On the first-floor level, above the southern porch and part of the adjacent staircase, is a series of chambers,[240] of which the purpose is not known. The walls of the two larger chambers are covered with marble, and their ceilings with mosaic. Only one stairway is now extant at the east. The minaret built by Mahomed II., which helps to buttress the south-east corner of the church, occupies the position of a second. Salzenberg’s Plate xiv. shows the stairway restored, but in Plate xiii. the northern one is removed to explain the arrangement of the part of the building to the south of it. On entering at the door of this north-eastern stairway one can either mount the ascending planes which wind round a well for light, or go to the left through a small lobby into the church. On the right steps ascend to the round building adjacent. The light ‘well’ once ascended the whole height of the staircase, which seems to have been formerly still higher, as the eastern wall of the church, which is here prolonged northwards, rises about four feet above the present roof of the stairway, and shows the remains of a window. These stairways may have been built by Andronicus Palaeologus in the fourteenth century, when he erected the buttress masses which are called pyramids by Nicephorus Gregoras. All these stairways however were additions to the building, probably built when the dome abutments were strengthened. The original staircases to the gynaeceum were in the four piers by the northern and southern walls of the church, and the steps from the gynaeceum to the base of the dome still remain.[241]