One of six buildings excavated at Lion Walk laid out in a fashion characteristic of Roman legionary barracks. The material used to construct the superstructure of the principal walls was sandy daub laid in the form of sub-dried blocks. These were placed over timber ground-plates which rested along the tops of the mortared plinths. Most of these buildings plinths had been robbed out in the early post-Boudican period so that only scatters of stones were left at the bottoms of the robber trenches. Traces of early floors were slight and it appears that initially the natural sand was used, perhaps with a covering of rushes. Internal partitions were provided by narrow walls of sandy daub, perhaps stretched by stakes.

The locations of the walls of the western part of the building were indicated by a number of shallow slots. Between AD 49-60/61 the original east-west wall along the centre of the block was replaced by another in roughly the same position. The western end of the new wall incorporated a post set in a large pit which must have cut the north-south plinth to the west. In the same wall but 3.2m to the east was another post also set in a pit. On the floor inside the north wall lay a group of burnt dates and a plum. A premature baby had been buried in a small pit (KF367) at the north side of the building (not clear if this is from the Fortress or early Colonia, though later is more likely).<1>