From MIT's Mims Bits blog:
Images from inside the Bahnhof data center show a world of Cold War-era security repurposed for the cyberwarfare of the 21st century.
If Wikileaks founder Julian Assange is trying to turn himself into a Bond villain, he's succeeded: the ongoing distributed denial of service attack against Wikileaks has forced his minions to move the site to a fortified data center encased in a cold war-era, nuke-proof bunker encased in bedrock. Really....MORE
Notice the lack of supports in the ceiling, aside from some kind of spray-concrete:
the rock from which this bunker was carved is hard enough that none are required.