Wolf's Lair is the name of a collection of bunkers in the Polish forest near Ketrzyn built by the Germans during WWII. Hitler spent much of his time here from 1941 to 1944, sometimes staying for up to six months at a time. Here he and his ministers such as Bormann and Goring would plan their military maneuvers and control occupied Europe. The bunkers were built well away from busy roads and were camouflaged from being spotted by airplanes above. The walls of the bunkers were up to eight metres thick and made of solid concrete. The area is the size of a small town and apparently around 2000 soldiers and officials lived here.
In July 1944, an assassination attempt on Hitler was made by some of his officers in one of the bunkers. One officer, von Stauffenberg, planted a bomb in briefcase and left it in the meeting room while he went 'to make a phone call'. The bomb killed four people but Hitler suffered only minor injuries. Today the site is marked by a plaque.
As the Russian army approached the bunkers from the west in 1944, the Germans retreated after exploding many of the bunkers. Today, the crumbling and twisted concrete blocks are what remain. The Germans also left mines around the area and it took ten years to clear all of them. I kept to the path just to be on the safe side.
Hitler's bunker. For an indication of the size, underneath the painted yellow square is the doorway.