13 items, numbered 3-15: maps and plans relating to fortifications in Ireland. Detailed descriptions are given at item level.
Following conservation work in February 1958, the 23 maps, plans and sections originally held at this reference were divided between MR 570 and MPHH 84. After further conservation work in January 1998, 13 of the drawings from MPHH 84 reverted to the original reference; three others remain extracted as MPHH 1/84
A damaged cover sheet or covering note filed with item (15) refers to '27 rough drafts'; this figure probably results from counting the four parts of item (12) individually.
For the items originally numbered 1-2 and 16-20, and the items originally numbered 21-23, see respectively