Wolin Island, a popular holiday resort in Poland's West Pomeranian region, contains a hidden historical site: the Wolin Underground City. Previously known as Vineta Battery, this complex of seven bunkers was constructed between 1935 and 1939 by the Nazis to guard the coastline. Though the German army attempted to destroy the site at the end of World War II, significant portions remain accessible.
The site now operates as a museum, with ongoing restoration and expansion efforts. After remaining a secret known only to high-ranking Polish officials for years, it opened to the public in 2014. Visitors must be accompanied by a guide to explore the nearly kilometer-long network of underground corridors, rooms, and shelters concealed beneath the coastal dunes.
Access to the site includes an interactive experience designed to bring history to life. Visitors are organized into a platoon and observed by a 'commander,' with military trucks, fences, and Soviet-style constructions contributing to an eerie atmosphere. The tour guides participants through various rooms, tunnels, and an engine room shelter. The temperature inside the bunker rarely exceeds 10 degrees Celsius (50 degrees Fahrenheit).
Inside the underground city, visitors can see decoding stations, an underground kitchen, a medical room, and a War Room command suite. The interior is described as cold and lifeless, with bare-brick wartime-style decorations and exposed concrete walls in some areas.
In contrast to the historical bunker, Wolin Island itself is a popular tourist destination known for its sandy beaches, Wolin National Park, and rich Viking history. Nearby towns like Międzyzdroje and Świnoujście are also popular holiday spots.
Other former military bunkers have also been repurposed. In Dorset, England, the Standby Generator Bunker, built in 1941 as part of RAF Ringstead's radar system, has been converted into a unique holiday accommodation. London's Kingsway Tunnel complex, believed to have been frequented by James Bond author Ian Fleming, is also set to open to the public, featuring an intelligence museum and an underground bar.