1999:187 - CHRISTCHURCH CATHEDRAL, Dublin, Dublin

An assessment was carried out in the medieval crypts of Christchurch Cathedral, Dublin, in February 1999, before proposed removal and replacement of the existing concrete floor. Only three small test-pits were excavated, to assess the depth of the concrete laid down by Street during the extensive renovations in the 19th century (1871–7). The assessment revealed, however, that there were no deep archaeological levels within the crypts. The crypt walls and piers stand directly on boulder clay in shallow foundation trenches.

However, during monitoring works by Helen Kehoe it was established that one of the pier bases sat directly on an earlier, unidentified stone structure. Along the east side of the crypts a thin organic deposit sat directly on boulder clay, and a small pit, which contained animal bones, was also found. Three small post-holes were also revealed in the central area. One of the test-pits was positioned along a drop in the floor level and a change in the pier base type, which was thought to mark a division in the date of the crypts, when the western end of the nave was extended in the mid-13th century. However, no original west wall was found.

At the extreme western end the remains of what may represent an earlier wall foundation were revealed, orientated north-south and bordered by an internal laneway on the eastern side. This laneway may mark the maintenance of a public route through the crypts of the cathedral after the nave was extended over the original line of Winetavern Street in 1234. Although no definitive evidence of burials in situ was revealed during the assessment, fragments of bone, which were probably human, suggested that there may have been surviving burials in the crypts; this was subsequently confirmed by Helen Kehoe during monitoring of the works.

The proposal to remove the entire crypt floor was subsequently dropped, and the ducting and other services were placed within the thickness of the existing concrete.