Properly known as Central Neutral Zone on pc and in the data base, as shown here. https://bdocodex.com/us/theme/3056/

This knowledge is bugged, in that once aquired from Xaviero Vitello, it does not register to your knowledge journal. 

The knowledge should be applied to Topography:Serendia:Peripheral Mountains Of Serendia  and would be the final piece of knowledge in the catagory.

This and two bits of bugged/missing Serendia Swamp knowledge are the only parts of the entire Topography subject I'm missing.