Inventory Reference 3326BD/ Minerals/ Birbury farm 102/Site A3S3 Formal Gradings Grading Grade II Grading Date 19/04/2020 GradingComment Site A3S3, defined as a structure pre-dating 60 years of age, is formally protected by the NHRA 1999 and receives automatic SAHRA protection as a site of High Significance with a Provincial Grade 2 Field Rating. Grading by: Karen Van Ryneveld Significance criteria Significance Categories Historical Sphere of Significance Provincial Level High