This is Pionen, an underground data center that belongs to Sweden’s largest internet service provider, Bahnhof. Located 30 meters under solid granite bedrock, it was built in a former bomb shelter and can withstand a direct attack with a hydrogen bomb.
This underground data center has greenhouses, waterfalls, and simulated daylight. If the power goes out, the backup power is provided by two German submarine engines. This place looks like the secret HQ of a James Bond villain.