There's a mysterious barge docked at Treasure Island, the former Navy base in the San Francisco Bay. The barge contains a structure built from shipping containers. According to CNET, whatever is inside those containers is related to a secret project underway inside Hangar 3 on the island, a former military base. CNET managed to trace the project back to Google. It seems likely that Google is either reverse-engineering a crashed alien spacecraft or prototyping a floating data center. CNET suggests the latter but my bets (and hopes) are on the former.