The 1840 edition named it, the 1870 edition repeated the error, and the misidentification quietly embedded itself into the cartographic record of the city. What the mapmakers had actually been looking at were the substantial east-west walls of two late medieval castellated town houses, a term referring to domestic buildings given battlemented or fortified features, which had once fronted onto the street in the Englishtown, the older of Limerick's two historic walled districts.

The confusion was not fully untangled until an excavation carried out by archaeologist Celie O'Rahilly in 1994, under licence 94E072, at Nos. 3 to 6 St. Nicholas Street. There was, as it happens, a real medieval church dedicated to St Nicholas in the vicinity, but it stood further north, close to King John's Castle, and was demolished in the aftermath of the siege of 1692. The Corporation subsequently built the Widows Alms Houses on that site. The houses on the excavated plot were something else entirely: quality stonework, architectural fragments recovered during the dig, and an arched doorway identified in the northernmost wall all pointed to buildings of some ambition. Three cuttings were opened across the site, and the first two revealed infilled cellars. The third, to the rear of No. 5, had been hoped to be undisturbed but proved to contain rubble of cut stone masonry, likely material from the partial demolition of the medieval houses before 1930s housing was constructed over them. No intact archaeological deposits were found in any of the three cuttings.

The site had also suffered more recent losses. A dividing wall between Nos. 4 and 5, which had survived successive rebuilds across the centuries, was demolished in 1992 under the Dangerous Buildings Act, along with part of the northernmost wall containing the arched doorway. The southern wall was in poor condition and underwent repair around the time of the excavation. What remains of the medieval fabric was, following the 1994 investigation, earmarked to be retained within any new development on the site. The walls themselves are not signposted or interpreted for visitors, and the casual pedestrian on Nicholas Street would have little reason to guess that the stonework visible here predates the 1840 map that so persistently got their story wrong.