2012:221 - St Patrick’s Grammar School, St Patrick’s Close/Kevin Street Upper, Dublin, Dublin

Test trenching was carried out on 2 March 2012 on the site of the proposed additional building to St Patrick’s Grammar School, St Patrick’s Close/Kevin Street Upper, Dublin 8. The proposed new school building is to be built in an empty space amid existing school buildings in the area between St Patrick’s Close and Kevin Street Upper, in the south-west quadrant of the site. The area is one of high archaeological potential, being very close to St Patrick’s Cathedral and within its precincts.

The site was concreted in many areas and this was broken by rock-breaker, after which a tracked digger using a narrow flat bucket was employed for the test excavation. Three test trenches were cut.

The development site as part of the precincts of the cathedral is shown in Speed’s map of 1610. It is just to the south of the cathedral and is outlined by St Patrick’s Close and Kevin Street Upper. The curved line of St Patrick’s Close seems apparent here, and the same short road later marked on maps as ‘Mitre Alley’ intersects present-day St Patrick’s Close with Kevin Street Upper, as it did up to the 19^th century. The development site is directly west of Mitre Alley which is marked on Rocque’s map of 1756 and the 1842 1^st edition OS map. On both Speed’s and Dinley’s maps, the Poddle and other watercourses are very apparent as they stream around the area of the site.

Bernard De Gomme’s map of 1673 would seem to suggest that the south-west area of the development site, if not the whole area of the proposed development, was completely engulfed by the river confluence at this date.

Bernard De Gomme’s map of Dublin 1673 showing the area of the site of the development (marked with red arrow).

Similarly, it would seem from Brooking’s map that this south-west area of the site was not developed but is marked ‘Poddle’ in 1728. By 1756, the site as we know it today was developed with housing as is shown on Rocque’s map and this continued into the 19^th and 20^th centuries as is clear from the OS maps.

From maps dating as late as the early 18^th century it seems that much of the south and west part of the development site, if not all the site, was actually engulfed by the Poddle and its confluence with the Commons Water and was only culverted in the 18^th century. The site as we know it today may have been subject at least to flooding until it was culverted.

Three test trenches were cut revealing unexpected depth. It was found in all three trenches that the natural level was 2.8-2.9m. Trenches 1 and 2 became flooded at the base soon after opening. The stratigraphy was much deeper than had been expected and revealed evidence of infilling of a waterlogged area. Evidence of possible refuse or tanning pits was found at the base of one of the trenches. Map research would corroborate the findings of the test trenching, strongly suggesting that this area was encroached by the Poddle River or subject to flooding. Thus this particular area of the site, or most of it, does not appear to have been built on till it was reclaimed in the early/mid-18^th century. Apart from some post-medieval pottery, there were no finds. Previous testing and excavation in the area has revealed evidence of pits, including rubbish and tanning pits, and it is possible that these may be found cut into the subsoil.

The school building will be supported by ground beams and piles. The ground beams will be situated about 1.8m above natural and cut features, while the drain should similarly be 1.3m above natural. Archaeological impact is restricted to a number of pits 0.625m x 0.65m and to the lift shaft which is approximately 2m x 2m. Monitoring of the development and resolution of any features found was recommended.

Judith Carroll & Company Ltd, Consultant Archaeologists, 11 Anglesea Street, Temple Bar, Dublin 2