Its a high-security data center run by one of Sweden’s largest ISPs. Located in an old nuclear bunker deep below the bedrock of Stockholm city, its one of the coolest data centers you can work in.

Royal Pingdom point us to some cool facts about the data center – Originally a military bunker and nuclear shelter during the Cold War era. The facility still has the code name from its military days: Pionen White Mountains. It is located in central Stockholm below 30 meters (almost 100 ft) of bedrock and can withstand a hydrogen bomb

It houses the Network Operations Center for one of Sweden’s largest ISPs Bahnhof. It uses German submarine engines for backup power and has 1.5 megawatt of cooling for the servers. Triple redundancy Internet backbone access ensures Pionen is one the best-connected places in northern Europe.

Of course the work environment is really cool with simulated daylight and greenhouses, waterfalls and a huge 2600-liter salt water fish tank!