Bahnhof Pionen

Pionen is Bahnhof's best-known Stockholm facility, built inside a decommissioned Cold War civil-defence bunker carved roughly 30 meters into the granite bedrock of Vita Bergen on Sodermalm. The site drew international attention after WikiLeaks hosted infrastructure there, and Bahnhof leaned into the setting with a deliberately theatrical interior featuring greenhouses, a simulated waterfall and submarine-style engine-room details alongside production colocation halls. Power runs through UPS rated at 1.1 MW output with roughly twelve minutes of runtime at full load, backed by 1.8 MW of N+1 diesel generation. Cooling combines a pair of N+1 heat pumps rated at 500 kW with dedicated liquid cooling units for redundancy. Bahnhof holds SSF Protection Class 3 and SSF Alarm Class 3 ratings for the site under Swedish security standards, plus ISO 27001 certification. The operator markets Pionen to Nordic enterprises wanting a physically hardened environment inside a historically unusual building rather than a standard raised-floor hall.