Wolf's Lair Kętrzyn

Wolf's Lair was Adolf Hitler's first Eastern Front military headquarters in World War II, located in the Masurian woods about 8 km from the small East Prussian town of Rastenburg.
Three security zones surrounded the central complex where the Führer's bunker was located.
The complex, which would become one of several Führer Headquarters located in various parts of occupied Europe, was built for the start of Operation Barbarossa - the invasion of the Soviet Union - in 1941.

Hitler first arrived at the headquarters on 23 June 1941. In total, he spent more than 800 days at the Wolfsschanze during a 3½-year period until his final departure on 20 November 1944.
On 25 January 1945, the complex was blown up and abandoned 48 hours before the arrival of Soviet forces.