2007:536 - Rathcoole House, Rathcoole, Dublin

An assessment was carried out at Rathcoole House, Rathcoole, Co. Dublin, on 19 and 20 November 2007. The proposed development site was located on the southern side of the Main Street of Rathcoole village and consisted of Rathcoole House and its former lawns. The site lies within the zone of archaeological potential for Rathcoole and is bound to the west by lands associated with an adjacent church and graveyard. This church dates to the early 18th century but was constructed upon the remains of an earlier ecclesiastical site of which nothing is known.
Rathcoole House is listed in the Register of Protected Structures in the South Dublin County Council Development Plan (2004–2010) as RPS 305, house and adjacent underground passage. The present building dates to the 1830s and is said to have been constructed over an earlier house. The house lies in the centre of the proposed development site and its former lawns lie to the south and the west. Pre-planning drafted development plans include the extension of Rathcoole House to the west, in order to create offices, stairways and a reception area. Plans also include the construction of an underground carpark and landscaping of the grounds.
Noting that the underground passage may have been extant, the site was subject to a geophysical survey in September 2007. The survey revealed five anomalies; one irregular reading was noted adjacent to the entrance of the house and four linear trends were recorded to the west and south-east of the house (Enright 2007).
Five north-east/south-west-orientated trenches (Trenches 1–5) and one east–west-orientated trench (Trench 6) were excavated across the site using a JCB fitted with a toothless bucket, in order to further assess the anomalies. Although no distinct feature associated with an underground passageway was uncovered during the testing, a number of structural features associated with Rathcoole House and grounds were discovered.
The excavation revealed that overburden comprising silty clays and stone blocks up to 1.65m deep had been deposited across the site over the past 100 years. Testing in the western end of the site revealed a north–south-orientated concrete surface, an associated structural wall and structural rubble within the western ends of Trenches 1–4. A boundary wall was also discovered in this part of the site.
Subsequent assessment of the OS and Land Valuation maps of Rathcoole show that this western end of the site was originally a road. This then fell into use as a narrow plot, within which two structures were situated. This plot was c. 12–14m wide and was sandwiched between the church to the west and Rathcoole House and grounds to the east; it belonged to Rathcoole House. On the maps of the site, a small rectangular structure is depicted in the north-western corner of the plot (this was not noted during the testing) and a long north–south-orientated structure was depicted as being situated along the eastern edge of the plot; this was the feature uncovered in the western end of Trenches 1–4.
The rubble and mortar remnants of another small rectangular structure were uncovered in the eastern end of Trench 1. This building is also visible on the OS map as being within the grounds of Rathcoole House; it appears to have been demolished by the time the second-edition OS map was drafted.
The remnants of a pathway and driveway leading from Rathcoole House to the southern end of the site were noted in Trenches 3 and 4. This feature is depicted on the OS maps. East of this feature a layer of mortar is visible running along the sections of Trench 4, which appears to be a front yard associated with the driveway.
A compact mortar/concrete surface was noted at the base of Trench 4. It was related to structural rubble and is depicted on the OS maps as another rectangular building located east of Rathcoole House. Two drainage features and a concrete slab were noted in the trenches, which probably relate to services associated with Rathcoole House.
No distinct feature that might be identified as an underground passageway was noted during the testing.
Recommendations within the relevant report state that archaeological monitoring of the site clearance and groundworks should be carried out. It is envisaged that the works will be carried out some time during 2008.
Reference
Enright, D. 2007 Geophysical Survey Report, Rathcoole House, South Co. Dublin. Unpublished Report, Margaret Gowen & Co. Ltd.