Wolf's Lair (Wolfsschanze) was Adolf Hitler's first Eastern Front military headquarters in World War II. 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. It was constructed by Organisation Todt.
The top secret, high security site was in the Masurian woods about 8 km from the small East Prussian town of Rastenburg (now Kętrzyn). Three security zones surrounded the central complex where the Führer's bunker was located. These were guarded by personnel from the SS Reichssicherheitsdienst and the Wehrmacht's armoured Führer Begleit Brigade. Despite the security, an assassination attempt against Hitler was made at 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 3½-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. The Red Army captured the abandoned remains of the Wolfsschanze on 27 January without firing a shot. It took until 1955 to clear over 54,000 land mines which surrounded the installation. Today only impressive concrete ruins exist.
Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.