1994:059 - DUBLIN: 20–25 Castle St., Dublin

Three licences were issued in respect of archaeological investigations conducted at this site. The site is located on the northern side of the street between the Dublin Corporation Rates Office (formerly Newcomen Bank) and the recently constructed 'Castlegate' apartment complex. It was occupied by a T-shaped redbrick building, with basement, a rear extension to the 'Carnegie Trust' building which fronts onto Lord Edward St. This building was demolished and the levels of the entire area were reduced, under supervision, by c. 2.5m prior to the commencement of an archaeological excavation in November 1994.

94E003
The archaeological potential of the site was initially evaluated by means of bore-hole testing, conducted at the site from January 18–24, 1994. A total of six bore-holes were inserted across the available areas of the site, the locations of which were agreed with the OPW. The results from the cores indicated that a c. 2.5m depth of modern rubble overburden existed, below which up to 2.9m of archaeological deposits remained intact. The upper surface level of the archaeological deposits ranged from c. 10.6m OD in the west to c. 9.7m OD in the east.

94E066
Further testing of the site was undertaken from May 18–20, 1994. This involved the excavation of a number of trial trenches in the eastern side of the site, as well as one in the basement of the existing building. The work was carried out to assess the level of disturbance caused by construction works in the 1920s and to further determine the exact levels of the surface of undisturbed archaeological deposits. The evidence from the trial trenches indicated that the exact surface of archaeological deposits lay at 9.65m OD beneath the existing building, and ranged from 9.49m–9.96m OD in the eastern part of the site.

94E177
Following negotiations between the developers, Dublin Corporation and OPW, a foundation design for the new building was agreed. The proposed basement carpark was to be linked to the existing 'Castlegate' apartment complex, which meant that the proposed floor slab level could not be higher than that of the adjacent building. It was agreed that the site would be archaeologically excavated down to the required levels (10.1m OD for a 13m wide area in the west of the site; 9.6m OD for the remainder). Following the completion of the excavation the entire site would be covered in a geotextile material, over which 300mm of hard-core would be laid. In this way the remaining archaeological deposits would be sealed. To this end the excavation of an area measuring 43m x 15m was carried out from November 14–December 23.

At least four phases of activity were identified, the latest of which was a laneway, Pembrook Court, which was constructed in the 17th century. It was c. 1.2m wide and was bounded on both sides by stone walls which were constructed on horizontal timber beams, which had formerly been used as structural timbers. The surfaces of the laneway were, in general, composed of stone cobbling with associated drains. However, fragments of the uppermost surface indicated that it was constructed in red brick.

Three habitation phases were uncovered. These took the form of property boundaries and timber structures. In all, evidence for 11 structures was uncovered, situated in seven property plots. While one structure appears to be medieval in date, the remainder, in general, appear to be Viking Age. The actual locations of the structures within the property plots were different to those uncovered in the adjacent site (Excavations 1993, 15–16) and it appears that the present line of this section of Castle St. bears no resemblance to the original form.

One unusual feature was a series of possible animal pens. These were constructed in stone, with associated surfaces of rough paving, and appear to be Viking Age in date.

The material finds from the site appear, in general, to be broadly similar to other comparable sites in Dublin. Work is now progressing on the post-excavation stage, and it is hoped to produce a report for publication in early 1996.

19 Monread Gdns., Sallins Rd., Naas, Co. Kildare