Wolf's Lair (German: Wolfsschanze; Polish: Wilczy Szaniec) was Adolf Hitler's first Eastern Front military headquarters in World War II. The complex, which would become one of several Fhrerhauptquartiere (Fhrer Headquarters) located in various parts of occupied Europe, was built for the start of Operation Barbarossa the invasion of the Soviet Union in 1941. It was constructed by Organisation Todt.
The top secret, high security site was in the Masurian woods about 8 km (5.0 mi) from the small East Prussian town of Rastenburg (now Ktrzyn, Poland). Three security zones surrounded the central complex where the Fhrer's bunker was located. These were guarded by personnel from the SS Reichssicherheitsdienst and the Wehrmacht's armoured Fhrerbegleitbrigade. Despite the security, the most notable assassination attempt against Hitler was made at the Wolf's Lair on 20 July 1944.
Hitler first arrived at the headquarters on 23 June 1941. In total, he spent more than 800 days at the Wolfsschanze during a 3-year period until his final departure on 20 November 1944. In the summer of 1944, work began to enlarge and reinforce many of the Wolf's Lair original buildings. However, the work was never completed because of the rapid advance of the Red Army during the Baltic Offensive in autumn 1944. On 25 January 1945, the complex was blown up and abandoned 48 hours before the arrival of Soviet forces.