The barrack house was an oblong structure originally divided into a row of 150 rooms, capable of accommodating 700 soldiers. A project undertaken in 1584 at a cost of 24,500 ducats raised the number of individual rooms to 616, holding three to four thousand troops, with separate officer quarters.

By 1586 the barrack house was complete. Architecturally speaking it became the town's pride and joy.

The east and north sides of the barracks, now used as the Heraklion Prefecture headquarters, 1920 - 1930 (Historical Museum of Crete, © S.C.H.S, Heraklion)