Walking in the forest of Gierłoż near Kętrzyn in northeastern Poland, you come up against huge, overturned blocks of concrete and massive structures resembling cement pyramids. How did they get here?

It is 1940. Adolf Hitler decides to invade the USSR. Dec. 18 he endorses the Barbarossa plan under which the Soviet Union is to be felled. In accordance with the führer's orders, quarters, secure from air raids, are to be built close to the border with the Soviet Union, from where operations on the eastern front can be overseen.

Hitler named the quarters Wolfsschanze (wolf's lair); the name hinted at his nickname Wolf, used in 1919 when he delivered speeches promoting Nazi slogans. In 1940 the area was closed to civilian populations and construction began. Only the most trusted people were employed as construction workers and teams of workers were regularly exchanged. The work continued throughout the winter and in May 1941 the lair was ready for its leader, although construction work still continued. Almost 20,000 people were employed, the materials transported from Germany. Successive stages lasted until 1944. The total cost: 36 million Deutschemarks.

Wolfsschanze was actually a small stronghold town with an area of 2.5 km. The quarters were divided into three zones; the main zone contained the bunkers of the Third Reich's top officials: Hitler, Bormann and Göring, among them. There were officers' casinos, cafes, a cinema and a sauna. In all, the complex included 80 buildings. The air-raid shelters had walls and ceilings from 5 to 8 meters thick. In smaller bunkers the walls were "just" two meters thick. There were also numerous houses with steel shutters and wooden barracks.

The quarters were accessible by three roads: from Węgorzewo, Kętrzyn and an airport five kilometers away. There were also technological facilities, a sewage treatment plant, a post office, a fire pond and hydrants.

The area was surrounded by a 10-km minefield up to 150 m wide, with high fencing preventing wild animals from entering. It took many years after the war to clear the area of mines. Over 54,000 mines were removed, costing many lives.

An abortive attempt on Hitler's life took place July 20, 1944. Many Germans had realized that Hitler's policy was bound to lead the Third Reich to catastrophe. The officers plotting against Hitler appointed Col. Claus Schenk Graf von Stauffenberg as assassin. Shortly after 12:30 p.m. he placed a briefcase with explosives under an oak table in the barracks where Hitler was to meet officers. Schenk left the room swiftly, saying he had to make a telephone call. He managed to flee to Berlin but shortly after was captured together with the other conspirators and executed.

Hitler miraculously survived, suffering only minor injuries, presumably thanks to the massive base of the table and its thick top on which maps were placed. A 1.5-meter crater formed beneath it.

The ruins of the Wolfsschanze, destroyed in January 1945 by the Germans as they fled the Red Army and the Polish Army, can still be seen.