They are not a ruin in any conventional sense, not a tower house or a church fragment, but the side walls of a late medieval town house, absorbed into the fabric of later buildings and largely invisible to anyone passing by. What makes the situation stranger still is that for decades those walls were doing structural duty for a 1930s three-storey block inserted between them, the new building borrowing the bones of the old one without acknowledgement.

The walls were formally described in the Urban Survey of Limerick compiled by Bradley and colleagues around 1989, which identified them as House B, noting the south wall at 1.5 metres thick and a round-headed doorway with chamfered limestone jambs still visible in the north wall between Nos. 35 and 36. The site was added to the Register of Historic Monuments on 17 June 1994. Excavations carried out by archaeologist Celie O'Rahilly under licence 94E0071 ext. examined Nos. 36 to 39 Nicholas Street and Nos. 1 to 3 Peter Street, the latter a short street formed between 1840 and 1870, presumably named because it once led towards Peter's Cell off Bishop's Street to the east. The excavations revealed that the medieval walls did not originally reach the present street line but stopped approximately four metres short of it, and that the southern wall retained, at first-floor level, the sides and part of the lintel of a late medieval fireplace in finely carved limestone. Behind the building, towards the rear of the plot, surveyors identified a vaulted undercroft, that is, a stone-arched basement space common in medieval urban properties for storage. Its eastern end wall had been blocked in two phases, and pottery recovered from the fill indicated that the vault was used as a dump for household rubbish during the eighteenth and nineteenth centuries. A carved stone recovered from near the base of the back wall proved to be identical to one still set in place in the surviving mantelpiece, a small detail that connects the two ends of the building's long history.

The site sits on the east side of Nicholas Street, which retains its medieval alignment as the principal street of the old Englishtown. Following the demolition of Nos. 36 and 37 in 1999, the standing medieval walls were recorded photogrammetrically, a technique that produces precise measured drawings from photographs, and a full report incorporating historical and cartographic research was prepared. The undercroft access ramp, first cut in 1995, ran from the rear of the Peter Street properties, curving westwards to reach the blocked arch. The archaeology here is not presented for visitors in any formal way, and the site sits in an urban streetscape that gives little away, but for anyone with an interest in how medieval Limerick was built and rebuilt upon itself, Nicholas Street repays a slow walk and a close look at the stonework that occasionally shows through.