Osowiec Fortress / Modlin Fortress / Waterway tunnel / Fort VIa / Zarzeczny Fort / Wisłoujście Fortress / Centralny Fort / Stadium bunker / Fort VIIIa / Bastion Filip / Fort I San Soglio / Pomiechowo Fort / Piętki Fort / Fort Va / bunker I / Fort IIc / Fort Carré / Staropola bunker / Bastion Król / Barbastelle's Tunnel / bunker AN / Fortification Latitude / Fort IId / Fort Iva / Bastion of Saint Gertruda / Malbork castle / Fort IIe / /
Important Underground Sites for Bats in Europe Poland