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.
The Arch of Constantine is situated between the Colosseum and the Palatine Hill. It was erected by the Roman Senate to commemorate Constantine I's victory over Maxentius at the Battle of Milvian Bridge in 312. Dedicated in 315, it is the largest Roman triumphal arch. The arch spans the Via triumphalis, the way taken by the emperors when they entered the city in triumph.
Though dedicated to Constantine, much of the decorative material incorporated earlier work from the time of the emperors Trajan (98-117), Hadrian (117-138) and Marcus Aurelius (161-180), and is thus a collage. The last of the existing triumphal arches in Rome, it is also the only one to make extensive use of spolia, reusing several major reliefs from 2nd century imperial monuments, which give a striking and famous stylistic contrast to the sculpture newly created for the arch.
The arch is 21 m high, 25.9 m wide and 7.4 m deep. Above the archways is placed the attic, composed of brickwork reveted (faced) with marble. A staircase within the arch is entered from a door at some height from the ground, on the west side, facing the Palatine Hill. The general design with a main part structured by detached columns and an attic with the main inscription above is modelled after the example of the Arch of Septimius Severus on the Roman Forum.