On low-lying ground to the south-west of Kildare town, a ruined nave and chancel church sits within a working graveyard, its five free-standing buttresses slowly parting from the north wall they were built to support, the partial south wall now pressed into service as the graveyard's boundary. The remains are overgrown, the limestone rubble coursed but rough, and most of the dressed stonework, the quoins, the jambs, the tracery, has long since been robbed out or collapsed. A drawing made by Austin Cooper in 1791 still records what was standing then: one, possibly two transepts, and a chancel window described as pointed with switchline tracery. The granite sill of what appears to be an even earlier window survives in the outer wall face, hinting at building phases that predate the structure as Cooper saw it.

The friary was Franciscan, founded sometime in the mid-thirteenth century, though the precise date remains uncertain. Gerald Fitz Maurice, ancestor of the earls of Kildare, is among those credited with the foundation, whether alone around 1260 or jointly with William de Vesci; an earlier date of around 1254 has also been proposed. The friars received a royal grant between 1276 and 1278, and the church became a burial place for the Kildare earldom: John Fitz Thomas, the 1st earl, was buried here in 1316, and both Thomas Fitz John, the 2nd earl, and his son Richard followed in 1328 and 1329 respectively. The friary surrendered in 1539 with a full complement of buildings, including a church, belfry, dormitory, hall, three chambers, kitchen, cemetery, and two gardens. By November 1540, jurors reported that everything except the church and most of the cloister had been burnt the previous May, the destruction attributed to O'Conor. The friary was re-established in 1621.

Archaeological work carried out in 2004 and 2005 ahead of commercial development revealed more than medieval fabric. Beneath and around the friary's footprint, excavators found a fulacht fia, a type of Bronze Age cooking pit associated with hot-stone boiling, a cremation burial, and an Iron Age kiln, indicating that the site had been in use long before the friars arrived. An earthen platform within the friary grounds, enclosed by three parallel ditches and known locally as a leper colony, yielded thirteenth-century floor tiles identical to those recorded at St Brigid's Cathedral, Dublin-type pottery, and a medieval horse harness pendant. The platform's exact function, whether hospital, animal enclosure, or temporary friary settlement during construction, was never conclusively established. The friary's garden area proved equally revealing: a carefully engineered drainage system, with central reservoirs designed to remove excess water in wet weather and retain it during dry spells, illustrated the practical sophistication of medieval monastic land management.