The Miedzyrzecz Fortified Region (MRU) is aunique fortification system on a European scale. Its surviving underground chambers are a valuable testimony of the history of the 20th century and an interesting tourist attraction in the Lubuskie region. Fortification began in 1936 and by the outbreak of the war Germans had built 106 reinforced concrete bunkers, including 21 connected by a network of underground tunnels with a total length of 30km at a depth of 40m. The system was supposed to protect the most vital section of the eastern border of Germany. The Miedzyrzecz Fortified Region stretches close to 80km between Gorzow Wielkopolski and Zielona Gora. The labyrinth of tunnels, railway stations and halls built tens of metres underground is fascinating due to the sheer scale of the project and the innovative technical solutions. A conveniently accessible underground trail to visit this monument can be found near Boryszyn about 6km north of Lubrza. The Miedzyrzecz Fortified Region (MRU) is one of the largest hibernation sites for bats in Europe. Each year over 30,000 of them winter here representing 13 different species. The most largely represented are the greater mouse-eared bat, the Daubenton’s bat, the Barbistelle, the long-eared bat (brown) and the Natterer’s bat. Miedzyrzecz Fortified Region (woj. Lubuskie) www.bunkry.pl