I don't have a copy of the Guinness Book of Records with me, but here is a web search result :
http://query.nytimes.com/gst/fullpag...pagewanted=all
The world's largest multilevel industrial building is an immense complex in Hong Kong owned by an American company, the CSX Corporation. The 14-story building at the Kwai Chung docks has 16 miles of roads inside, mostly of three lanes, and handles 10,000 trucks bearing containers each day. Companies like Adidas, Wal-Mart, Target, Next and Liz Claiborne all lease space in the building for various tasks, like inspecting garments.