What makes it quietly arresting is the detail: a knight carved in full plate armour, his sword hanging from a belt at the waist, his feet shod in articulated sabatons with short pointed toes, lying beside a woman whose low turret headdress still retains traces of its original quatre-diaper foil work. The relief of both figures is, as the art historian John Hunt noted in 1974, unusually low, which gives the whole surface an almost drawn quality rather than the rounded projection you might expect.

The tomb commemorates Sir Christopher St Lawrence, who died in 1462, and his wife Anne Plunket, daughter of a Plunket of Ratoath. It was placed in a chantry, a small chapel endowed for the saying of masses for the souls of the deceased, given by the St Lawrence family around the same year. The monument is considered a product of what Hunt identified as the Meath school of tomb carving, a regional tradition recognisable by its particular conventions of armour and figure treatment. The inscription running around the chamfered edge of the slab is mostly in Black Letter script, though the closing phrase, "me fecit" (made me), switches to Roman letters. That shift is tantalising because it was presumably where the maker signed his name, but the signature itself is illegible. The tomb surrounds are carved with figured niches on the east and west ends: saints Catherine, Peter, and an archbishop and abbess on one end; the Crucifixion flanked by Our Lady and St John, St Michael slaying the dragon, and angels with censers on the other. The long sides carry empty niches but the shields above them are intact, displaying the arms of families connected to the St Lawrences and Plunkets, including Fleming, Cusack, Bellew, and the Arms of the Passion.

St Mary's Church stands in Howth village and is accessible on foot from the harbour area. The tomb sits at the east end of the southern aisle and is best viewed up close, where the carved details of the armour and the lady's costume reward slow looking. The iron railings prevent direct access but allow a clear view from multiple angles, and the canopy, while functional, does not obscure the monument. The empty niches on the long sides are a reminder that some elements of the original programme may never be fully explained.