The Citadel was surrounded by 3 fortifications as bridgeheads, that were made up by branches of the Mukhavets River and moats (ditches), fortified by earthworks 10 m high with redbrick casemates inside. The 3 fortifications were named after two towns: Russian name for the city of Kobryn in Belarus, Terespol in Poland and Volyn, a historic region of Volhynia majorly located in Ukraine. The Kobrin Fortification was the biggest in the fortress, located in the northeastern part, shaped like a horseshoe, featured 4 fortification curtains, 3 detached ravelins and a lunette in the western part, East Fort and West Fort.