| ΟΟ 281 | Line of North Wall Y; Poros Building Wall; North Wall Northeast Annex; On Paving Slabs and Clay Floor North of Wall Y | 6 May 1949 | 2nd half of 5th B.C. | |
| ΟΟ 282 | Line of North Wall Y; Poros Building Wall; North Wall Northeast Annex; Fill to North of Line of Wall Y with Limestone Working Chips | 7 May-6 Jun 1949 | Middle of 5th B.C. | |
| ΟΟ 283 | Line of North Wall Y; Poros Building Wall; North Wall Northeast Annex; Fill to North of Line of Wall Y with Limestone Working Chips | 7 Jun 1949 | Middle of 5th B.C. | |
| ΟΟ 284 | Line of North Wall Y; Poros Building Wall; North Wall Northeast Annex; On Edge of Trench for Wall | 7 Jun 1949 | Middle of 5th B.C. | |
| ΟΟ 285 | Line of North Wall Y; Poros Building Wall; North Wall Northeast Annex; Against North Face of Second Course of Wall Y at East; Some Limestone Chips | 7 Jun 1949 | Middle of 5th B.C. | |
| ΟΟ 286 | Line of North Wall Y; Poros Building Wall; North Wall Northeast Annex; Against North Face of Second Course of Wall Y at East; Clay Fill Against North Face; Large Block of Y | 7 Jun 1949 | 6th B.C. | |
| ΟΟ 293 | Line of North Wall Y; Poros Building Wall; North Wall Northeast Annex; On Grey Clay; Uneven Level Outside Level of Poros Building | 7-9 May 1949 | 5th B.C. | |
| ΟΟ 294 | Line of North Wall Y; Poros Building Wall; North Wall Northeast Annex; On Grey Clay; Clay Fill North and East of Wall Y, and on Wall Z | 11-12 May 1949 | | |