The shelter in the curtain of the III front of the IV bastion was designed for the safe and hidden movement of personnel under the forward rampart to the territory of the II ravelin.
It was built of brick in 1882 during the modernization of the fortress facilities according to Obruchev's project. The shelter was closed with gates on both sides. In the post-war period, buttresses were destroyed at the exit from the II ravelin.
With the beginning of hostilities in June 1941, using the passage to the vala (sortia), the evacuation of civilians, families of the command staff who lived in the nearby DNC was carried out. Later, in his memoirs, the object was referred to as an "underground passage" in the direction of the city, which in turn formed the basis for the birth of the legend of the "dungeons" of the Brest fortress.
The legendary Major Gavrilov, the last defender of the Brest Fortress, was captured here on July 25, 1941.