They were uncovered not by chance but by archaeological excavation in 1993, emerging from ground that had once belonged to a medieval Augustinian friary, a complex that had stood in this part of the city for nearly three hundred years before being dissolved and largely forgotten.

The Augustinian Friary of the Holy Trinity was founded around 1259 by a member of the Talbot family, one of the Anglo-Norman dynasties that shaped medieval Dublin. The Augustinians, also known as Austin Friars, were a mendicant order, meaning they relied on charitable support rather than endowments, and their houses typically occupied urban plots where they could serve and draw from a town population. By 1282, the friary was well established enough to be named in the will of William de Stafford, who left legacies to several churches before departing on pilgrimage to the Holy Land. When Henry VIII's dissolution of the monasteries reached Ireland, the friary was surveyed in 1540 and recorded as comprising a church with a belfry, a hall, and a dormitory, a modest but functional set of buildings that had served the community for roughly two and a half centuries. After dissolution, the site passed out of religious use and was gradually absorbed into the evolving urban fabric of the city.

The friary does not survive above ground in any visible form, but its archaeology is more substantial than the streetscape suggests. Test excavations in 1995 indicated that structural remains survived on the eastern side of Cecilia House, and work the following year exposed a section of wall incorporating a relieving arch, an arch built into a wall to redistribute its weight and prevent stress fractures, along with a corner tower. The site sits in the area around Cecilia Street in Temple Bar, and while there is nothing to see at street level, the sequence of investigations across 1993, 1995, and 1996 established that a meaningful portion of the medieval friary still lies just below the surface, waiting, as it has for centuries, beneath the city.