Bahnhof
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Bahnhof AB is a Swedish internet service provider, colocation operator, and cloud provider best known for Pionen, its data center built inside a Cold War nuclear bunker beneath central Stockholm. Founded in 1994 as Sweden’s first independent ISP, Bahnhof has since built out a small but distinctive network of self-owned, self-operated data centers concentrated in Stockholm, with additional facilities in Malmö and a new bunker-based site under development in Gothenburg. Its differentiator is less about scale than about heritage sites, security theater, and a strict “Based in Sweden” data-sovereignty guarantee, alongside a colocation and cloud business it markets to enterprises, media, finance, and privacy-conscious customers.
Bahnhof operates as a cloud provider and colocation provider, with facilities at the following locations:
FACILITY OPERATOR
Phone: +46 10 510 00 10 Email: [email protected]
Bahnhof Data Center Locations
- Gothenburg, Sweden Bunkerberget PENDING REVIEW
Bunkerberget is a World War II-era bunker in Gothenburg's Gamlestaden district that was later used by manufacturer SKF before Bahnhof acquired it in 2025 to become its second bunker-based data center after Pionen. - Malmö, Sweden Sparven (Tranquility Base) · +46 10 510 00 10 PENDING REVIEW
Sparven occupies a former telecommunications central in Malmö where, per independent facility listings, Scandinavian and European fiber routes converge. - Stockholm, Sweden Pionen (White Mountains) · +46 10 510 00 10 PENDING REVIEW
Pionen is a former Cold War civil-defence bunker roughly 30 meters under Stockholm bedrock that gained global notoriety in 2010 when WikiLeaks used it for co-location hosting.
By Continent
Common Questions
Is Bahnhof's Pionen facility still in active use?
Yes. As of the mid-2020s, sources confirm the facility, opened on 11 September 2008 inside a former nuclear bunker under Stockholm's Vita Bergen park, remains an operational colocation data center and the network operations center for Bahnhof's ISP business.
Does Bahnhof offer AI or GPU-specific colocation/cloud infrastructure?
No genuine, specific evidence of AI-optimized GPU clusters, liquid cooling, or dedicated AI/ML infrastructure was found at any current Bahnhof facility in available sources.
How many data centers does Bahnhof operate, and where?
Sources vary between 4 and 7 depending on when they were published, but consistently describe multiple sites in Stockholm (including Pionen, Thule, S:t Erik and Gullan/Kista), one in Malmö (Sparven), and a new bunker-based facility, Bunkerberget, announced for Gothenburg in 2025.
What is distinctive about Bahnhof's approach compared to larger colocation and cloud providers?
Bahnhof deliberately repurposes decommissioned Cold War-era bunkers and industrial caves into data centers, as seen in Pionen (Stockholm) and Bunkerberget (Gothenburg), and markets a strict Swedish-soil data residency guarantee alongside its colocation and cloud offerings.
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