https://www.nortfort.ru/kgorka/foto_f10_e/
130 mm B-1-13 gun emplacement, The Fort (Krasnaya Gorka Fort) - Northern Fortress
It was intended for 11-inch howitzers. There is the small underground town with concreted galleries, powder cellars and soldiers barracks around it. Round form...
gun emplacementthe fortkrasnaya gorkanorthernfortress