Fort XIII "San Rideau". Built between 1892 and 1896. It was almost identical with Fort IX "Brunner" - however it had one armoured turret less in the vault, instead it had a right-hand-side gun casemate on two tiers. There were also some differences in the caponier structure. Beside Fort IV "Optyń", Forts IX and XIII were the most powerfully armed armoured units of the Przemyśl Fortress.