St. Kevin's Park does not announce itself loudly. It looks, from the street, like a quiet green space. What it actually contains is several centuries of Dublin's religious and social turbulence, compressed into a few hundred square metres.

The church here was dedicated to Kevin of Glendalough and first recorded in historical annals in 1226, though it was already listed among the possessions of the Canons of Holy Trinity in 1179. From the 13th century it formed part of the Manor of St. Sepulchre, under the jurisdiction of the Archbishop of Dublin. The building was re-roofed in 1582 but had fallen ruinous by 1630, and the structure visible today dates from around 1780. The site's most contested history, however, centres on the burial of Archbishop Dermot O'Hurley, who was executed at Hoggens Green on 20 June 1584 following imprisonment and torture by government authorities after his return from Rome. O'Hurley had been ordained Archbishop of Cashel in 1581, and his grave here became a place of veneration for Catholics for several hundred years; by 1609 pilgrims were arriving in such numbers that the church was rebuilt and a new entrance made. By 1698, during the Penal Laws, the building had been offered to the Huguenot community as a place of worship and cemetery, though the graveyard continued to receive Catholic burials until the end of the 19th century. An excavation in 1967 recovered medieval graves and coins, and medieval paving tiles have also been recorded on the site.

The park is freely accessible, and the ruins of the church are visible from the path. Along the south wall of the church stands the Leeson altar-tomb, an altar-tomb being a chest-shaped monument raised on legs or a solid base, roughly table-height, with an inscribed slab on top. The sexton told the Reverend R.S. Maffett in 1904 that it bore the oldest date in the churchyard. The inscription records that it was erected in 1685 by Hugh Leeson, a Dublin brewer, then beautified by his son Joseph in 1741, and renewed in 1852. Hugh's grandson, also Joseph Leeson, was created Earl of Milltown in 1760, a title whose heraldic motto, "Clarior e tenebris," meaning "brighter from the darkness," has a certain unintentional aptness for a graveyard that has absorbed so many difficult histories. The tomb itself carries a coat of arms with an esquire's helmet, mantling, and what appears to be a martlet as a mark of cadency, though, as Maffett noted, the tinctures are not given, and whether Hugh Leeson himself is actually buried beneath it remains uncertain.