The Czechoslovak fortification system from the 1930´s consisted of border lines, and inland lines to stop the enemy if they broke through the border zone. One of these inland lines was the Prague line. Between 1936 and 1938 a 112 km long chain of fortifications with the total number of 830 light bunkers, divided into 17 construction sectors, was built for the defense of the capital.

Light fortifications were designed on the principle of side barrage. The blind front walls faced the enemy and were protected with massive stone ramparts covered with a thick layer of soil. The front wall on both sides extended into protective wings which forced the enemy to enter the barrage if they wanted to silence the weaponry in the side embrasures of the bunker. There were usually several neighboring bunkers involved in the barrage.

A survey of the construction sector A4 Druzec found that the road on the embankment from Dolni Bezdekov to Bratronice, which crossed the defence line, prevented continuous lateral barrage. Because the height of the road was almost identical to a standard light bunker type 37, the two-sided bunker was incorporated directly into the body of the road.

In comparison with standard light bunkers, that one in Dolni Bezdekov was extended by six meters by adding a central room. The resulting structure is unique. The object was manned by usual crew of seven men (2 observers, 2 machine-gun shooters, 2 loaders and a soldier, operating the manual fan).

The atypical Bezdekov bunker was constructed in summer 1937. In June 1939, when the Czechoslovak inland fortifications were demolished by the German occupiers, both side casemates were damaged by explosives during an attempt to tear out the embrasures. To avoid destroying the road by further explosions, the interior of the fort was filled up with stone and concrete. The bunker remained in that state until May 1992, when members of the Military History Club Prague started the challenging work of reconstruction with the intention to allow public access into the bunker.

In the casemate on the right side of the bunker, there is a heavy machine-gun ZB type 37, installed on a machine-gun mount manufactured in Czech Arms Factory in Strakonice, with counterweight. In the left embrasure is a light machine-gun ZB type 26 placed on a mount manufactured in the Arms Factory Brno.

Both mounts are equipped with the device to allow the soldiers to aim at night or in poor visibility – on the little situation sketch are marked reference points of proven range. Bunkers could communicate with field telephones, optical signals through periscope, with signal flags or flares. There are hand-grenade chutes in the object in case enemy should reach the walls of the bunker.

In 1999 to 2008 the Bezdekov bunker was opened to public six times a year and it has been seen by some five thousand visitors. At present the object A4/51 is accessible only four times a year – on last Saturdays in May, June, September, and on the National Day, October 28 (10 AM to 5 PM). The museum is situated between the villages of Dolni Bezdekov and Bratronice in the Kladno district, about 35 kilometres West from Prague.