Bahnhof’s Pionen data centre operates about 30 metres beneath Stockholm in a former civil-defence bunker. Renovated and opened in 2008, it combines server areas with rock tunnels, plants under artificial light and an artificial waterfall.
Built during the Cold War for emergency protection, the bunker is carved into solid rock, which provides a physical barrier. Pionen’s infrastructure is designed to keep equipment running if normal services are disrupted; backup power has included diesel generators originally designed for marine use.
The facility is operated by Swedish internet company Bahnhof, whose infrastructure was used by WikiLeaks in Sweden during a period of intense global attention. Sweden’s constitutional protections for expression and publishing do not give internet services absolute immunity for hosted material; applicable protections depend on the circumstances.
