County: Dublin Site name: DUBLIN: 29–34 Thomas St. (rear)
Sites and Monuments Record No.: N/A Licence number: 95E0110
Author: Margaret Gowen
Site type: Watercourse
Period/Dating: Medieval (AD 400-AD 1600)
ITM: E 714516m, N 733859m
Latitude, Longitude (decimal degrees): 53.342556, -6.280273
The site lies within the documented western suburb of the medieval city. Thomas St. is medieval in date, with St Thomas's Abbey to the south of the site. The present church of St Katherine's, which lies to the immediate west on the other side of a lane, is thought to be located on the site of a medieval church of the same name. In addition, historical sources document the presence of a watercourse known as 'Colman's Brook'. The river was divided up into millraces to power various mills, one of which, the Watte Mill, was located somewhere to the west of the site.
The site, which was covered in concrete, was divided into two levels, with the western side 1.3m lower than the eastern side. A total of nine trenches were excavated, six on the western side and three on the eastern. The test-trenching was supervised on site by Linzi Simpson.
The east side
The trenching revealed what was possibly a small watercourse, at the northern end of the site, beneath almost 3m of rubble. The recovery, within a grey silt deposit, of several worked planks associated with two posts may suggest some form of timber revetment, possibly oriented east-west. However, access was restricted at the side of the site and no conclusions could be drawn.
To the south of the possible watercourse a deep deposit of wet organic material with an obnoxious smell possibly relates to tanning activity on the site. The remains of a timber barrel set into the organic deposit were also located, a common feature on such tanning sites. Unfortunately there were no finds from the organic deposit.
The west side
The west side of the site was 1.3m lower than the east but was level with the laneway which bordered the site on the west. The trenching produced no evidence of the watercourse or the possible tanning activity located on the east side of the site. The ground was made up of a green, friable 'garden soil'-type deposit which produced one sherd of a medieval floor-tile. There was no evidence of any burials which may have been associated with St Katherine's graveyard to the west.
The remains of a clay-bonded wall footing was located at the north-west corner of the site, possibly orientated east-west; however, it was very badly damaged. Several post-medieval limestone walls were also located.
Rath House, Ferndale Rd, Rathmichael, Co. Dublin
