Bullets were found inside the wooden structure, belonging to both Nazi and Soviet troops, indicating it was possibly a site where fighting occurred in 1944 when the Red Army reconquered the area.
The facility was found seven meters underground and consists of a staircase and three underground corridors that extend from it.
The tunnels were hollowed out using a mining method, according to Dr. Dariusz Kopciowski, Lublin Voivodeship Conservator of Monuments.
"For now, the construction has to be extracted and at the same time studied, so that the investor can safely ‘situate’ the building in this place…great care is necessary," Kopciowski said.Construction on the parking lot was halted following the discovery.