Nobody is entirely sure where it stood. No trace of it survives above ground, and neither Speed's map of 1610 nor Rocque's of 1756 shows anything at the locations scholars have proposed. What is known is that the street itself was still being called St. Kevin's Port as late as the nineteenth century, a ghostly echo of a structure that had long since vanished from the fabric of the city.

St. Kevin's Gate appears in the documentary record from around 1213, when it was noted in Archbishop Alen's Register. Its importance as a boundary marker becomes clearer in 1326-7, when an inquisition into the extent of Dublin's city limits, heard before Thomas Fitz John, Earl of Kildare and justiciary of Ireland, described the city's southern edge running from the gate outward toward Donnybrook and the River Dodder. A 1603 perambulation of the city boundaries traces a route along the south side of St. Stephen's Green to the gate, then turning northward up a lane toward what is now Bishop Street, where a stone cross still lay in the roadway. The Down Survey map of Newcastle barony, drawn around 1655, labels the spot 'Kevvensport' and places it at the south-eastern corner of the city's outer defences, with St. Stephen's Green lying just to the east. Complicating matters further, a Dublin City Assembly Roll of 1465 records that the Carmelite prior and convent were granted a laneway running between the church of St. Stephen's and the church of St. Kevin's, along with the right to build a gateway at each end, raising the possibility that two separate structures both went by the same name at different times.

There is nothing to see at the site today in any conventional sense, which is part of what makes it worth thinking about. The junction of Wexford Street and Protestant Row, marked on the Friends of Medieval Dublin map from 1978, is as close as current scholarship can place the gate, though researchers Bradley and King noted plainly in 1987 that its precise position in the street remains unknown. Walking the area with the 1603 boundary description in hand, tracing the route from St. Stephen's Green northward through what are now busy south city streets, gives some sense of how the medieval city's edges were drawn and how thoroughly they have been absorbed into the ordinary life of the place.