2014:485 - The former National Irish Bank, Nos 23-7 College Green/6 and 7 Church Lane and 25-27 St Andrew’s Street, Dublin 2, Dublin

Monitoring was carried out at the former National Irish Bank, at College Green, Dublin 2, during the conversion of the building from a bank into a retail and residential unit. The attractive and ornate building, executed in the Gothic-Italian style, was opened as the Union Bank in 1864 and was designed by William G. Murray and expanded by Thomas Drew, both well-known architects working in Dublin at this time. The bank is a Protected Structure, No. 1994. The site lies within the Zone of Archaeological Potential and ‘constraint circle’ of a ‘mound’ (DU018 020132), the site of which lies immediately east of the former bank. This mound is thought to have formed part of a Viking burial ground in College Green known as ‘Hoggen Green’ which is likely to have contained many other burial mounds in this general area. This site may even have been the thingmot or assembly mound of the Viking settlement of Dublin, the focal point of the all administrative, judicial and social activities. It is one of two such mounds that survived until the 17th century.

The discovery of Viking remains at Suffolk Street increased the importance of this site and the possibility of more burials although it did have a deep basement, which was retained in the new development. The only intervention was the removal of part of the slab along with deep excavation for a lift-pit and escalator, which provided an opportunity to establish whether or not the basement had removed all the deposits. The monitoring progamme did establish the basement was cut into a natural yellow sticky clay in places, which sat over hard black riverine gravels. These yellow clays, where they survived, contained fragments of brick, which could be dated to the 19th century. The riverine gravels are very distinctive, hard and gritty, and composed of limestone fragments. In some locations shattered bedrock lay just 2m below the present ground level.

The excavation for the lift-pit was carried out in the western side of the building and measured approximately 7m east-west by 4m wide by 2m in depth, exposing an existing lift-pit, which measured 2m square with foundations that were 1.5m in depth. The excavation for the main lift-pit exposed a pure black smelly organic material, which contained brick and fragments of timber, along with what appeared to be a hessian or roofing felt.

Profile: west section

0 - 0.4m: Reinforced concrete slab. 

0.4 - 0.6m: Mixed stony beige clay – very hard and natural but with the odd fleck of brick in the upper fill level .

0.6 - 0.8m: Hard dark grey silt with bits of timber – this is a natural deposit.

0.8 - 1.4m: Very hard beige clay with small stone and lenses of black silt

1.4 - 1.7m: Hard riverine silt: dark black limestone with small stones, 2mm in diameter – this is a natural deposit.

The general profile is of hard black silt and gravel, containing small stones. The upper levels contain fragments of moss and timber, probably roofing material.

The excavation for the escalator pit, measuring 9.5m long by 4.5m in width, involved the removal of the thick basement slab, which was 330mm in depth and had to be removed mechanically. The pit was excavated to 1.4m in depth below the present slab and this exposed natural undisturbed ground which, in this location, was composed of dark grey silt and gravel. A mix layer of clay, silt and sticky grey/green clay was located in the north-east corner which extended for 0.80m in length east-west and was 0.1m in depth. This represented a disturbed ground associated with the construction of the basement. An examination of this deposit revealed several fragments of 19th-century pottery and clay pipe stem. The pit was extended to 1.8m in depth in two locations and this exposed dark grey and gravel riverine deposits. No archaeological deposits or features were noted.

28 Cabinteely Close, Cabinteely, Dublin 18