The imposing buildings of the north wing date to the Frankish period and look like a fortress. The building with the Gothic arches on the windows, the latter two-storey building that has been identified as the home of the despot and the Kantakouzenos family, (dated between 1350 and 1400), the kitchen and the cisterns, belong to this wing.
The NW side of the square is occupied by a single two-storey building that is a complete imperial residence and represents a typical example of the architecture of the time, also found in other areas of the Byzantine territory. The imperial building consists of a small vaulted basement, the first floor with eight apartments and the second floor with a single space known as the Hall of the Throne or Chrysotriklinon, which is a 36m x 10 m rectangular space with many arched windows, round skylights and eight fireplaces that were used for heating.