In mid-2000 this exact cave was also used for some LARP (Live Action RPG) games. One of bigger polish LARPs events called Orkon, was organised nearby. I did actually play Alien vs. Predator themed game there, in the middle of the night, where Stajnia cave was the Alien-Egg base. I remember it as a respawn point, after getting killed by Marines, Spec-Naz or Predator.