2025:713 - 29-30 Usher Quay, Dublin, Dublin

Cumming Group, on behalf of PI Hotels & Restaurants Ireland Ltd, engaged Aisling Collins of (ACAS) to carry out archaeological testing in advance of the proposed hotel development at Ushers Quay, Dublin 8. This work is required to satisfy an archaeological monitoring/excavation condition attached to the site under the Planning Register.

The site is located at Nos. 1, 1a and 2 Usher Street, Dublin 8 and Nos. 29/30 Usher’s Quay, Dublin 8 (Eircodes D08 YY11 and D08 VYX7). Usher’s Quay is in St Audoen civil parish, Usher’s Quay Ward, and was an electoral division in Dublin City.

The archaeological testing at Usher’s Quay revealed natural ground deposits located at depths of c.5m below present ground level (c. minus 1.2m OD). (Note: the current riverbed of the River Liffey lies at a depth of c.5.3m below present road level of Usher’s quayor approximately minus 1.1m OD).

Above the natural deposits (present in all test trenches) lies a deep black organic deposit which is up to 1.4m in depth. Finds retrieved from the organic layer included glass fragments, leather off-cuts, pottery, clay pipes and animal bone, all dating to the late 17th – early 18th century. The organic material probably represents a single event of backfilling and reclamation of the river foreshore area which took place in the late 17th/early 18th century. This was done to build up the ground and ready the area for the development of the quays and construction of the Rocque building plots in the early part of the 18th century.

The testing also confirmed the presence of post-medieval building remains surviving to depths of c.2.5-3m below present ground level (above the black organic deposit). These included house basement walls along the Usher’s Quay frontage along with outbuildings, possible cellars, floor levels and boundary walls across the remainder of the site. The upper courses of the walls lie at depths of between 0.5m to 0.8m below existing ground level with walls surviving up to 1.8m in height. The ground plans of these buildings, including warehouses, backyards, laneways and property plots, are illustrated on Rocque’s detailed map of Dublin dated 1756 and the Ordnance Survey maps dated 1847 and 1897.

There was no evidence of any medieval structures such as timber revetments or stone buildings within the trenches excavated. However, the testing results are based on the inspection of 7 short test trenches (c.3m long) that were excavated across the site. Hence, it’s possible, that in the areas between trenches, archaeological features, including revetments, boundary ditches, watercourses, pits, fish traps and even human burials may be present, particularly at the natural clay/gravel levels. Also, any such features could date from the prehistoric to medieval/post-medieval periods.

In conclusion, and based on the current site development plans, there will be significant impact to below-ground deposits and structures. All the post-medieval building remains, and archaeological stratigraphy identified during testing, will require archaeological excavation down to the natural gravel/clay levels (hotel basement formation level).

The perimeter piling or pile wall will consist of c.196 piles of 0.60m diameter. The internal basement piles will consist of c.105 piles most of which will be 0.6m in diameter – all piles will extend to depths of c.14/15m below present ground level. It is purposed to monitor all pile guide trenches excavations and lower-level pile extrusions, particularly in the black organic reclamation deposits, for finds retrieval.

The proposed basement level of the new hotel is to be excavated archaeologically down to the riverine gravel substrate prior to commencement of construction – a depth of at least c.5m below present street level. The excavation process should incorporate the recording of any 18th/19th-century foundations located within the rubble layer extending to c. 2.5m depth. These wall remains are indicated on Rocque’s map of Dublin dated 1756 and the first edition Ordnance Survey maps. The levels below the post-medieval building foundations consist of dark brown/black organic deposits which contain artefacts dating to at least the 17th/18th centuries. The upper levels of the natural strata are located at average depth of c. 5m below present ground level (or street level) or c. minus 1.2m OD.

A detailed methodology for archaeological excavation has been developed in consultation with the contractor/engineers and submitted to the National Monuments Licencing section & Dublin City Archaeologist for review/approval.