Built in 1877-1882, this fortified structure is one of 12 fortifications that make up the outer ring of the former Königsberg Castle, formerly known as the "Night Feather Bed in Königsberg". At the end of World War II on April 7, 1945 AD, the garrison in . surrendered "Fort XI" is practically without a fight, for this reason it is the least disturbed fortress and still retains its shape and form among other Kaliningrad fortresses. Nowadays, guests who visit "Fortress No. 11 Dennhof" have the possibility to touch the pure history and see with their own eyes part of the defense system that existed before 1945 AD, besides, there are exhibits and interesting objects such as the original German gate, iron stairs, corridors of barracks and observation .