This construction of 7 meters by 8 meters with a capacity of 100 m3 could be supplied by the well or by tanks pulled by horses. The initial function of this tank was to provide a water reserve for the construction of the blockhouses on the site.
Once the construction of the blockhouses was completed, the tank served, according to sources, as a ‘swimming pool’ in summer, or more probably as a refectory for the garrison.
