When they were finishing the separate, new section of Stockton in 1957 or 1958, the section next to The Oval, before there were walkways and landscaping, the building was locked but a couple of us found out that there was some kind of concrete tunnel you could drop into to get into the basement and then up into the new building. We were among the first kids to tour the new building and were very proud of (and a little guilty about) our caper. They put only the lower grades over there and it had its own library; those of us sixth graders who had worked in the main building library in 5th grade were allowed to go over and run the new little library.
The design of the building duplicated the revolutionary hexagonal classroom shape of the 1951 Stockton annex. (See blogpost on May 31, 2011 for more info on the design)