2010:298 - Institute of Technology, Tallaght, Dublin

Several medieval (late 12th–14th-century) ditches, a pit, and post-medieval stone drains were identified in a series of test-trenches opened across the greenfield areas to the east of the existing college buildings and north of the site of the Archbishop’s palace. The identified features include a large ditch that may have enclosed the palace and a series of shallow furrows and pits, probably the result of domestic occupation on and cultivation of the lands to the north of the palace. Three test-trenches were excavated on the western side of the campus but the ground at these locations had been previously disturbed and no features were identified. The depth of topsoil across the site ranged from 0.3m to 0.56m. Spoil from the trenches and from sections excavated into the archaeological features was scanned with a metal detector but no artefacts were recovered.
A large north–south-orientated ditch, F19, that may have marked a boundary was one of the features identified on the south-eastern end of the site, within the constraint area of the historic core of Tallaght, DU021–037. This ditch was 2.7m wide and 0.85m deep. Water ingress at the base of the ditch and the silty lower fill indicate that the ditch had held water. The lower fill, F21, contained a sherd of Leinster cooking ware, snail shell and fragments of charcoal. There were sherds of Leinster cooking ware, fragments of animal bone and a piece of flint debitage within the upper fill. A smaller contemporary ditch, F18, was uncovered 2.3m to the west of ditch F19. It was 0.7m wide and 0.25m deep and contained a sherd of Leinster cooking ware. An east–west-orientated ditch, F3, was identified 74m to the southeast of ditch F19. It was 2.4m wide and 0.26m deep and sherds of Dublin coarseware were recovered from the upper fill. Adjacent to this ditch was a truncated deposit, F5, from which a sherd of Leinster cooking ware was retrieved.
A drainage ditch, F24, 1.6m wide and 0.55m deep, was uncovered 50m to the south-west of the large boundary ditch F19. It was filled with silty clay that contained frequent snail shells, fragments of mortar, occasional fragments of animal bone and charcoal flecks but no datable finds. Two land drains were identified c. 8m to the west of the ditch F24. The southern drain was dated to the 17th century by a sherd of North Devon gravel-tempered ware.
A series of features were also uncovered on the north-eastern end of the site, to the north of the RMP. These include a medieval ditch, F10, medieval gully, F16, cultivation ditches F27, F29, a pit, F37, and a large drainage ditch, F39, of unconfirmed date, as well as a series of post-medieval stone drains.
The ditch F10 was located 160m to the north of the medieval ditch F3 and was orientated north-east/south-west. It measured 1m wide and 0.3m deep and was filled by silty clay with very occasional fragments of animal bone and a heavily eroded sherd of Leinster cooking ware. A larger ditch, F39, was located 40m to the south-east. It was 1.8m wide and 1.4m deep and had three levels of fill, each of which contained snail shells indicating that the ditch had served as a drain. No finds were recovered from the section excavated into this ditch but it may correspond with a field boundary shown on Rocque’s map of 1760. The pit F37 lay to the east of the ditch F39. It was 0.85m by 0.5m by 0.12m and there were charcoal flecks and a sherd of Leinster cooking ware within the fill. The cultivation ditches F29, F27 and gully F16 were all orientated north-east/south-west and were uncovered 130m and 200m to the west of pit F37. They ranged from 0.45m to 0.6m wide and 0.07m to 0.12m deep. Sherds of Leinster cooking ware were recovered from ditch F29 and from the gully.