The Miedzyrzecz Reinforced Region was built by Nazis between the I and the II World War. It was extended and partly rebuilt during the II World War. It used to serve as a fortified defense line and was supposed to defend the Third Reich. It’s situated in western Poland between rivers: Oder and Warta. Even today it remains one of the most enormous systems of this type.
The Miedzyrzecz Reinforced Region is a net of reinforced concrete bunkers, steel domes, and kilometers of concrete antitank barriers called “dragon teeth”. Around 21 bunkers were connected together with subway situated 30-50 meters under ground. This labyrinth has nearly 30 kilometers length.
The concrete stairs lead from the main tunnel and side tunnels to overhead part of structure – the bunker “Panzerwerk”. The bunkers walls were 25 cm thick. The bunkers were fitted with military weapons: machine guns, flame throwers and motor throwing grenades machine which has throw ability to 140 min per minute.
The whole net of bunkers and underground system of the Miedzyrzecz Reinforced Region were fitted with essential equipment – lighting system, ventilation, waterworks, sewage system, communication. In addition to military equipment and war rooms there were also stockrooms, barracks, ambulances, engine room, ventilators, etc.
The fortifications were gained by Red Army in the 30 th January 1945. Abandoned by people basements have become bats’ property – around 30.000 of bats belonging to 12 species winter here every year. They often are rare species and are imminent to extinction. In 1999 the basements of the Miedzyrzecz Reinforced Region bacame nature reserves – “Nietoperek” and “Nietoperek II”. Since then visiting the undergrounds is only possible with a guide in determined tourist part.