A caltrop is an area denial weapon made up of usually four, but possibly more, sharp nails or spines arranged in such a manner that one of them always points upward from a stable base. Historically, caltrops were part of defences that served to slow the advance of troops, especially horses, chariots, and war elephants, and were particularly effective against the soft feet of camels. In modern times, caltrops are effective when used against wheeled vehicles with pneumatic tires.
The Siegfried Line, known in German as the Westwall, was a German defensive line built during the late 1930s. Started in 1936, opposite the French Maginot Line, it stretched more than 630 km (390 mi) from Kleve on the border with the Netherlands, along the western border of Nazi Germany, to the town of Weil am Rhein on the border with Switzerland. The line featured more than 18,000 bunkers, tunnels and tank traps.
The Mannerheim Line was a defensive fortification line on the Karelian Isthmus built by Finland against the Soviet Union. While this was never an officially designated name, during the Winter War it became known as the Mannerheim Line, after Finnish Army's then commander-in-chief Field Marshal Baron Carl Gustaf Emil Mannerheim. The line was constructed in two phases: 1920–1924 and 1932–1939. By November 1939, when the Winter War began, the line was by no means complete.
An area denial weapon is a defensive device used to prevent an adversary from occupying or traversing an area of land, sea or air. The specific method may not be totally effective in preventing passage, but is sufficient to severely restrict, slow down, or endanger the opponent. Some area denial weapons pose risks to civilians entering the area even long after combat has ended, and consequently are often controversial. An area denial weapon can be part of an anti-access/area denial (A2/AD) strategy.
The Czech hedgehog is a static anti-tank obstacle defense made of metal angle beams or I-beams. It is similar in shape to metal knucklebones, although on a much larger scale. The hedgehog is very effective in keeping light to medium tanks and vehicles from penetrating a line of defense; it maintains its function even when tipped over by a nearby explosion. Although Czech hedgehogs may provide some scant cover for attacking infantry, infantry forces are generally much less effective against fortified defensive positions than mechanized units. The author of the Czechoslovak invention is Major František Kašík.
No man's land is waste or unowned land or an uninhabited or desolate area that may be under dispute between parties who leave it unoccupied out of fear or uncertainty. The term was originally used to define a contested territory or a dumping ground for refuse between fiefdoms. It is commonly associated with World War I to describe the area of land between two enemy trench systems, not controlled by either side. The term is also used metaphorically, to refer to an ambiguous, anomalous, or indefinite area, regarding an application, situation, or jurisdiction. It has sometimes been used to name a specific place.
The Toblerone line is a 10 km long defensive line made of "dragon's teeth" fortifications built during the Second World War between Bassins and Prangins, in the Canton of Vaud, Switzerland. These lines of defensive blocks can be found all over Switzerland, though more commonly in border areas. Their purpose was to stop tank invasions. The 2,700 9-ton concrete blocks that make up the defences are similar to the shape of the Toblerone chocolate bar, which gave its name to the line. Since the line has been left to nature since its construction, it was decided to keep these concrete blocks and to make a hiking trail along their route.
The Mius-Front was a heavily fortified German Nazi defensive line along the Mius River in the Donbas region of the Soviet Union and Ukraine during World War II.
The Koningshooikt–Wavre Line, abbreviated to KW Line and often known as the Dyle Line after the Dijle (Dyle) river, was a 60 kilometres (37 mi)-long fortified line of defence prepared by the Belgian Army between Koningshooikt and Wavre which was intended to protect Brussels from a possible German invasion. Construction on the KW Line began in September 1939 after World War II had begun but while Belgium itself remained a neutral state. It was subsequently extended southwards from Wavre towards Namur. The line itself consisted of bunkers, anti-tank ditches, and barricades including so-called Cointet-elements and played a key role in Allied strategy during the German invasion of Belgium in May 1940. However, its role in the actual fighting was ultimately minimal. In 2009 an inventory of surviving emplacements was begun.
A mine-clearing line charge is a device used to create a breach in minefields under combat conditions. While there are many types, the basic design is for many explosive charges connected on a line to be projected onto the minefield and then exploded, detonating any buried mines, thus clearing a path for troops to cross.
Anti-tank obstacles include, but are not limited to:
A pillbox is a type of blockhouse, or concrete dug-in guard-post, often camouflaged, normally equipped with loopholes through which defenders can fire weapons. It is in effect a trench firing step, hardened to protect against small-arms fire and grenades, and raised to improve the field of fire.
The Kiev Fortified Region is a fortified district in the Kyiv area, a complex of defensive structures, consisting of permanent and field fortifications and engineering obstacles. It was built in the period from 1929 to 1941 for the protection of the old border of the USSR. The total length of the fortified region is about 85 km between the flanks, which are anchored on the river Dnieper, and the depth of the defensive zone ranges from 1 to 6 km.
A fortified district or fortified region in the military terminology of the Soviet Union, is a territory within which a complex system of defense fortifications was engineered.
The Árpád Line was a line of fortifications built in 1941-44 in the north-eastern and eastern Carpathian Mountains, along the border of Kingdom of Hungary. It was named after Árpád, the head of the Hungarian tribes. The main function of the Line was to protect Northern Transylvania and Carpathian Ruthenia from the east.
Sergey Vladimirovich Surovikin is a Russian army general who serves as head of the Coordinating Committee for Air Defence under the Council of Defence Ministers of the Commonwealth of Independent States (CIS) since September 2023.
The flexible defense is a military theory about the design of modern fortifications. The examples of "flexible" defense-lines are not based on dense lines of heavily armed, large and expensive concrete fortifications as the systems such as the Maginot Line were. Their protective capacity hinges on multiple lines of obstacles and small shelters fitting into the environment. They are "flexible" because soldiers are not locked in pillboxes, but fight instead in easily replaceable open earth-wood made positions, while bunkers serve only as shelters during bombardments. As a result, they are able to adapt to the opponent's movements, and there are no easily targeted large buildings in these lines.
During the Russian invasion of Ukraine that started in 2022, both belligerents have built extensive fortifications in the respective theaters of war, which have proven pivotal for the war effort. Various defensive structures, such as trenches, bunkers, anti-tank barriers, and urban fortresses, were built to slow down advances and protect key areas. The defensive structures combine traditional military engineering and the innovative use of modern technology for defense-in-depth. The nature of these conditions has been likened to the trench warfare of World War I.
Barrage is a military term covering a wide range of structures, devices, or measures for destroying something to constrain or impede the movement of troops and forces.
