Fortifications of the inner German border The fortifications of the inner German border comprised a complex system of interlocking fortifications and security zones long and several kilometres deep , running from the Baltic Sea to Czechoslovakia . The outer fences and walls were the most familiar and visible aspect of the system for Western visitors to the border zone , but they were merely the final obstacle for a would - be escapee from East Germany . The complexity of the border system increased steadily until it reached its full extent in the early 1980s . The following description and the accompanying diagram describe the border as it was around 1980 . Travelling notionally from east to west , an escapee would first reach the edge of the restricted zone ( " " ) , a closely controlled strip of land 5 kilometres ( 3 . 1 mi ) wide , running parallel with the border . Evading the patrols and watchful inhabitants of the " Sperrzone " , the escapee would have reached the first of the border fences . The signal fence ( " Signalzaun " ) , around from the actual border , was lined with low - voltage electrified barbed wire which activated alarms when touched or cut . Beyond the signal fence was the " protective strip " ( " Schutzstreifen " ) . It was brightly lit by floodlights in many places to reduce an escapee ' s chances of using the cover of darkness . Guard towers , bunkers and dog runs were positioned at frequent intervals to keep a round - the - clock watch on the strip . Crossing the " Schutzstreifen " , the escapee would next reach the floodlit control strip , often called the " death strip " in the West . Tripwire - activated flare launchers were situated at various points to help the border guards to pinpoint the location of an escape attempt . The last and most formidable obstacle was the outer fencing . In some places there were multiple parallel rows of fences , each up to several metres high , with minefields in between . The fences were not electrified but were booby - trapped with directional anti - personnel mines at intervals of , each one of which was capable of killing at a range of up to . Finally , the escapee had to cross whatever natural obstacles were on the western side of the border fence as well as traversing a strip of cleared ground that was up to 500 meters ( 1640 ft ) wide . While crossing this outer strip , the escapee would appear in clear view and shooting range of the border guards before reaching the safety of West German territory . Restricted zone . The " Sperrzone " , a wide area to which access was heavily restricted , was the rear segment of the border defences . When it was established in May 1952 it included a number of villages and valuable agricultural land . Although the land continued to be farmed where possible , many of the inhabitants were expelled on the grounds of political unreliability or simply because they lived inconveniently close to the border line . In some instances , entire villages were razed and the inhabitants were relocated far to the east . Those who remained behind were required to be completely loyal to the regime and support the border guards , helping them by watching for strangers and unfamiliar vehicles . Even so , they had little freedom of movement ; special permits were required to enter the zone and farmers worked under close supervision . They could enter and leave the zone an unlimited number of times but could not travel to other villages within the zone . Curfews were imposed to prevent inhabitants from crossing the border under the cover of darkness . The " Sperrzone " was not fenced off but was marked with warning signs . The entry roads were controlled by checkpoints ( " Kontrollpassierpunkte " ) through which only authorised individuals could pass . The first layer of border fences , the signal fence , lay on the far side of the " Sperrzone " to control access to the protective strip or " Schutzstreifen " adjoining the border itself . Signal fence . The signal or " hinterland " fence ( " Signalzaun " ) was the first of the border fences , dividing the " Sperrzone " from the more heavily guarded protective strip ( " Schutzstreifen " ) adjoining the actual border . Its purpose was to provide the guards with an early warning of an escape attempt . The fence itself was not a particularly formidable obstacle , standing only high . At the top , middle and bottom , rows of electrified barbed wire strands were attached to insulators . Cutting the wires or pulling them out of place resulted in an alarm being activated , alerting the guards to a possible breach of the fence . In practice , though , the border guards found that the fence frequently malfunctioned . The signal fence also had a wide control strip on its eastern side . The fence was built on open high ground wherever possible , to ensure that intruders would be silhouetted against the sky and thus be more easily spotted . By mid - 1989 , of signal fencing had been constructed along the border . Watchtowers and bunkers . The border defences were monitored from hundreds of watchtowers regularly spaced along the " Schutzstreifen " . Initially they were simple wooden huts mounted on legs between high , usually constructed from locally sourced timber . Most were replaced with concrete watchtowers from the late 1960s onwards in conjunction with the upgrading of the border defences . By 1989 , there were 529 concrete towers along the length of the inner German border and a further 155 towers of steel and wood construction , as well as various little - used observation platforms in trees . The concrete towers were prefabricated from sections that could be assembled within a few days . Their height could be varied by reducing the number of sections as required . They were connected to an electricity supply and telephone line and were equipped with a powerful 1 , 000 - watt searchlight ( " Suchscheinwerfer " ) on the roof that could be directed at targets at any position around of the watchtower . The windows could be opened to enable the guards to open fire without leaving the tower . In addition , the towers had firing ports emplaced in the side walls below the guard compartment . The towers were principally of three types : Around a thousand observation bunkers also stood along the length of the border . Most common was a small concrete bunker known as an " earth bunker " ( " Erdbunker " ) , usually recessed into a depression in the ground with a view along the guard road and border fence . It was constructed from two base sections , each high with a cross - section of . It terminated in a third section that had two firing ports in the front side and one or two on each of the other sides . The roof was a separate component nesting on top of the concrete bunker , which could accommodate up to two soldiers . Guard dogs . Dog runs ( " Kettenlaufanlagen " ) were installed on high - risk sectors of the border . The dogs were generally were chained to steel cables up to long . The dogs were occasionally turned loose in temporary pens adjoining gates or damaged sections of the fence . By the 1970s , there were 315 dog runs with 460 dogs . This figure increased steadily until a total length of of dog runs had been installed by mid - 1989 , with 2 , 500 dogs employed as watchdogs and another 2 , 700 so - called " horse dogs " . Patrol roads . Rapid access to all parts of the border line was required for a quick response to escape attempts . This was initially a problem for the East Germans , as few patrol roads existed along the border in its early years . Patrols typically used a footpath that ran inside of the fence , alongside the control strip . When the " modern frontier " was constructed in the late 1960s , an all - weather patrol road ( " Kolonnenweg " , literally " convoy way " ) was installed to enable the guards to travel rapidly to any point along the border fence . It consisted of two parallel lines of perforated concrete blocks , each block measuring approximately wide and long . The blocks were pierced with four rows of rectangular concrete drainage holes . In some places they were laid crosswise to provide a continuous roadway . They were also occasionally used as foundation stones for structures such as towers and revetments and to create foundations on which towers were constructed . The " Kolonnenweg " usually ran between the control strip ( on the border side ) and the watchtowers ( on the inland side ) . Around of patrol roads were built along the border , of which around was fully paved . In addition to the main " Kolonnenweg " , there were numerous short access roads built through forests and fields in the " Schutzstreifen " . Constructed from the same perforated concrete as the " Kolonnenweg " , these gave the border guards rapid access from the hinterland to the border line . Some civilians were permitted to use these access roads for forestry or farm work , though only with special permission . Control strips . The control strips ( " Kontrollstreifen " ) were lines of bare earth running parallel to the border fences . They were not an obstacle as such but provided a simple and effective way for the border guards to monitor unauthorised travel across the border . It was almost impossible to cross the strip without leaving footprints , enabling the border guards to identify otherwise undetected escape attempts . They could learn how many individuals had crossed , where escape attempts were being made and at which times of day escapees were active . From this information , the border guards were able to determine where and when patrols needed to be increased , where improved surveillance from watchtowers and bunkers was required , and which areas needed additional fortifications . There were two control strips , both located on the inward - facing sides of the border fences . The secondary " K2 " strip , wide , ran alongside the signal fence to the rear of the " Schutzstreifen " , while the primary " K6 " strip , wide , ran along the inside of the border fence or wall . The K6 strip ran almost uninterrupted along the entire length of the border . Where it ran across roads , the road surface would be ripped up to make way for the control strip ; where the border ran along streams and rivers , the strip was constructed parallel with the waterways . In places where the border was prone to escape attempts , the control strip was illuminated at night by high - intensity floodlights ( " Beleuchtungsanlage " ) installed on concrete poles , which were also used at vulnerable points such as rivers and streams crossing the border . The strip was patrolled several times a day by guards , who would inspect it carefully for signs of intrusions . In the West , the control strip became known as the " death strip " ( " Todesstreifen " ) because of the shoot - to - kill orders given to the border guards . The East Germans preferred to call it by the more euphemistic name of the " action strip " ( " Handlungsstreifen " ) . It was also nicknamed the " Pieck - Allee " ( " Pieck Avenue " ) after East Germany ' s president Wilhelm Pieck ( 1949 – 60 ) . The Soviets had pioneered the use of control strips on the borders of the USSR . The same technique was adapted for use in Germany when the border was first fortified from May 1952 onwards , at a time when it was still policed by Soviet troops . The construction of the control strip in 1952 was carried out by local villagers conscripted into work brigades . One of those involved , a resident of the Thuringian village of Kella , later recalled : The control strips were later maintained by a specialist engineering corps , the " Grenzpioniere " . They used wide harrow s towed by KT - 50 bulldozers and copious quantities of herbicide to keep the strip free of vegetation . Anti - vehicle barriers . Anti - vehicle barriers along the inner German border developed throughout its history . In the early days , the East Germans blocked border crossings by simply tearing up the road surface , digging ditches and using the earth and rubble to build ramparts that physically blocked the carriageways . These were then enhanced with wire and wooden posts . As border fortifications developed into permanent barriers , purpose - built obstacles became standard . The commonest types were Czech hedgehogs ( " Panzersperre " ) or " cheval de frise " ( " Stahligel " or " steel hedgehogs " ) . These anti - vehicle devices were constructed from three or four pairs of long rails welded together to form a steel obstacle weighing over – heavy enough to stop a motor vehicle from pushing them aside . Distributed at intervals calculated to be narrow enough to prevent even the smallest East German vehicle , such as Trabant s , from passing between them , they became a common sight along the entire Inner German border and the Berlin Wall . Rows of anti - vehicle ditches or " Kraftfahrzeug Sperrgraben " ( " KFZ - Sperrgraben " ) were built during the era of the " modern frontier " . These lined of the border and were absent only where natural obstacles such as streams , rivers , gullies or thick forests made such barriers unnecessary . The ditches were constructed as a V - shaped cut about deep , with a steeply sloping western edge and shallow eastern edge . The western edge was faced with concrete slabs that were deep . They proved to be an extremely effective obstacle , preventing almost any type of vehicle from crossing . Outer fences and walls . The border fences were constructed in a number of phases , starting with the initial fortification of the border from May 1952 . The first - generation were crudely built barbed - wire fences ( " Stacheldrahtzäune " ) standing between high . The fence was overlooked by watchtowers located at strategic intervals along the border . It was , however , a flawed obstacle . In some places it was so poorly constructed or maintained that livestock were able to wander unhindered across the border . In a few places gaps were purposefully left with lowered gate poles in front of them and anti - vehicle Czech hedgehog barricades behind . The fences were strengthened in the late 1950s , particularly in areas with a high number of escapes . Parallel rows of barbed - wire fences were built , with concertina wire added between the fences in some places to further hinder escapees . The outer fence was often located very close to the actual border . A further obstacle was added by placing short wooden anchor posts about outwards from both fences . Barbed wire was strung between them to form a V - shape to hinder lateral movement by escapees . In some low - risk areas , only a single fence was installed . A " third generation " border fence , much more solidly constructed , was installed in an ongoing programme of improvements from the late 1960s to the 1980s . The entire fence line was moved back to create an outer strip ( see below ) between the fence and the actual border . The barbed - wire fences were replaced with a barrier that was usually between high . It was constructed with expanded metal mesh ( " Metalgitterzaun " ) panels . The openings in the mesh were generally too small to provide finger - holds and were very sharp . The panels could not easily be pulled down , as they overlapped , and they could not be cut through with a bolt - or wire - cutter . Nor could they be tunnelled under easily , as the bottom segment of the fences was partially buried in the ground . In a number of places , more lightly constructed fences ( " Lichtsperren " ) consisting of mesh and barbed wire lined the border . The fence was not continuous , but could be crossed at a number of points , other than the official border crossings . Gates were installed to enable border guards to patrol up to the border line and to give engineers access for maintenance on the outward - facing side of the barrier . Like the fence itself , the gates were designed to be escape - proof . They were hinged from the outside but opened inwards and the pivot pins were welded to prevent their removal . They were chained and locked with heavy - duty padlocks , and a sharp saw - toothed steel strip was bolted to the top of the gates to prevent them being climbed . In some places , villages adjoining the border were fenced with wooden board fences ( " Holzlattenzaun " ) or concrete barrier walls ( " Betonsperrmauern " ) standing around high . Windows in buildings adjoining the border were bricked or boarded up , and buildings deemed too close to the border were pulled down . The barrier walls stood along only a small percentage of the border – of the total length by 1989 . A notorious example was in the divided village of Mödlareuth , where the border ran along the course of a stream that bisected the village . When the border was first fortified in 1952 , a wooden board fence was erected just inside East German territory . It was replaced in 1966 by a long , high concrete wall built through the village on the East German side of the stream . The village was nicknamed " Little Berlin " for its resemblance to the divided city . The name was well - earned , as the wall was constructed along very similar lines to the one in Berlin . Like the Berlin Wall , its top was lined with sewer pipes or steel pipes to prevent it from being climbed and its interior perimeter was floodlit at night . Anti - personnel mines . The outer border fences were lined with anti - personnel mine s designed to kill or injure would - be escapees . The mining of the border began in 1966 ; by the 1980s , some 1 . 3 million mines of various Soviet - made types had been laid . The mines were usually laid in a standardised pattern of a rectangular box , , containing three rows of mines . The most common type was the Soviet - made PMD - 6M mine . However , its wooden construction made it unreliable and prone to decay . The PMD - 6Ms were later replaced by more durable plastic mines of the PMN - 2 , PMP - 71 and PPM - 2 types . Most of the mines were pressure - activated , requiring someone to step on one to detonate it , with the exception of the tripwire - activated POMZ - 2 stake mine . The minefields were not marked on the East German side , though " Achtung ! Minen ! " signs were often posted by the West Germans on their side . The mines were a hazard to civilians on both sides of the border ; they were frequently set off by animals such as deer and they could be washed out of position by rain or floods . It was not unknown for mines to travel hundreds of metres into fields and streams on either side of the border . In 1970 , the East Germans began to introduce the SM - 70 ( " Splittermine - 70 " ) directional anti - personnel mine , mounted on the border fence itself . Some 60 , 000 SM - 70s were eventually installed . It was given various descriptions in the West such as " spring gun " or " self - firing device " , though to the East Germans , it was known as the " automated firing device " ( " Selbstschußapparat " ) . The device consisted of a horizontally oriented cone filled with of TNT explosive into which was embedded around 80 small sharp - edged steel cubes . It was fitted to the inward - facing side of the border fence at intervals of around . The device was triggered if the tripwire connected to the firing mechanism was pulled or cut . It was potentially lethal to a maximum range of around , though its effective lethal range was 25 metres ( 82 ft ) . On one occasion , when a deer fell victim to an SM - 70 , an observer noted that " an approximately 5 meter area appeared as if it had been worked over by a rake . " By 1976 , SM - 70s had been installed along 248 km of the border and conventional minefields lined another 491 km . The mines were eventually removed by the end of 1984 in the face of international condemnation of the East German government . Outer strip . Until the late 1960s the border fortifications were constructed almost up to the actual border line . The later " modern frontier " , by contrast , incorporated a wide strip of cleared land on the Western side in front of the border fence . The outer strip ranged in width from to as much as in some places . It gave the border guards a clear field of fire to target escapees who had made it over the fence and provided a buffer zone where engineers could work on maintaining the outward face of the border defences . Access to the outer strip was very tightly controlled , to ensure that the guards themselves would not be tempted to escape . Although often described by Western sources as a " no - man ' s land " , it was in fact wholly East German territory ; trespassers could be arrested or shot . Border line . The actual border line between West and East Germany was located on the far side of the outer strip . It was marked by granite border stones ( " Grenzsteine " ) , square with a + carved on the top and the letters " DDR " on the west - facing edge . In August 1967 , the East Germans erected 2 , 622 distinctive border markers or " barber ' s pole s " ( " Grenzsäule " or " Grenzpfähle " ) , each located about apart . They were made of concrete and were painted with the black , red and gold colours of the German flag . Some can still be seen " in situ " today . A metal East German coat of arms , the " Staatsemblem " , was fixed to the side of the column that faced West Germany . The column terminated in a metal spike . This was intended to stop birds using the border markers as a perch and thereby prevent them defecating on the coat of arms . On the West German side there were no barriers of any kind , nor even any patrol roads in most areas . Warning signs ( " Grenzschilder " ) with messages such as " Achtung ! Zonengrenze ! " ( " Danger ! Zonal border ! " ) or " Halt ! Hier Zonengrenze " ( " Stop ! The zonal border is here " ) notified visitors of the presence of the border . Foreign military personnel were restricted from approaching the border to avoid clashes or other unwanted incidents . Signs in English and German provided notifications of the distance to the border to discourage accidental crossings . No such restriction applied to Western civilians , who were free to go up to the border line . There were no physical obstacles to stop them actually crossing it , and there were incidents of West Germans crossing the border to steal East German border markers as souvenirs ( at considerable risk , since the East German border guards sought to prevent such " provocations " ) .