BlockhouseA blockhouse is a small fortification, usually consisting of one or more rooms with loopholes, allowing its defenders to fire in various directions. It is usually an isolated fort in the form of a single building, serving as a defensive strong point against any enemy that does not possess siege equipment or, in modern times, artillery, air force and cruise missiles. A fortification intended to resist these weapons is more likely to qualify as a fortress or a redoubt, or in modern times, be an underground bunker.
BunkerA bunker is a defensive military fortification designed to protect people and valued materials from falling bombs, artillery, or other attacks. Bunkers are almost always underground, in contrast to blockhouses which are mostly above ground. They were used extensively in World War I, World War II, and the Cold War for weapons facilities, command and control centers, and storage facilities. Bunkers can also be used as protection from tornadoes. Trench bunkers are small concrete structures, partly dug into the ground.
Battle of BerlinThe 'Battle of Berlin, designated as the Berlin Strategic Offensive Operation by the Soviet Union, and also known as the Fall of Berlin', was one of the last major offensives of the European theatre of World War II. After the Vistula–Oder offensive of January–February 1945, the Red Army had temporarily halted on a line east of Berlin. On 9 March, Germany established its defence plan for the city with Operation Clausewitz. The first defensive preparations at the outskirts of Berlin were made on 20 March, under the newly appointed commander of Army Group Vistula, General Gotthard Heinrici.
Anti-aircraft warfareAnti-aircraft warfare, counter-air, anti-air, AA guns, layered air defence or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action". It includes surface based, subsurface (submarine launched), and air-based weapon systems, associated sensor systems, command and control arrangements, and passive measures (e.g. barrage balloons). It may be used to protect naval, ground, and air forces in any location.
