This historic attraction offers a unique insight into Poland during the Second World War. The region was a fortified military defense line created by the Nazis between the Oder and Warta rivers during the 1930s.
The area consists of approximately 100 concrete defensive structures interconnected by a network of underground tunnels stretching nearly 100km in length. The underground system, which is home to subterranean railway stations, workshops and engine rooms, has even more to offer – this unique habitat has become a perfect home for bats that live here and can be spotted during a visit!