Fort IV in Kaliningrad, Military fortification in Kaliningrad, Russia.

Fort IV Gneisenau is an elongated hexagonal fort surrounded by a water moat. A two-storey central building with interior rooms stands between two inner courtyards holding battle positions, symmetrically placed either side of the central poterne and covered by an earth rampart. The central gorge section was demolished after the war and roads now run to its left and right.

Fort IV was built in Königsberg in 1872 and named after August von Gneisenau, the Prussian field marshal who fought at Waterloo. It stood on the route of the Red Army's main advance in 1945 and was heavily damaged; it was breached about seven times, only two of them through-and-through. After the war the central gorge section was demolished, used as a sapper training ground, and roads were laid to either side.

The fort's name honours August von Gneisenau, the Prussian field marshal who fought at Waterloo. Visitors can still see the moat, the two inner courtyards with their battle positions, and the earth embankment covering the two-storey central building. The central gorge section was demolished after the war and used as a sappers' training ground, with roads laid on either side.

The fort is accessible to visitors who want to explore the defensive installations and outdoor grounds. Wear comfortable walking shoes since the terrain is uneven and involves multiple levels and different areas to navigate.

The fort was hit by heavy-calibre artillery about seven times, but only two of those hits pierced the structure. The central gorge section was later demolished and used as a sapper training ground, and roads now run to its left and right. Shell craters and small machine-gun positions still line the perimeter of the water moat.