Beneath the foundations of the Shelbourne Hotel on St Stephen's Green, somewhere under the grand Victorian facade and the lobby that has hosted treaty negotiations and society gatherings alike, lies the site of a seventeenth-century residence that has left no visible trace whatsoever.

The house belonged to William Petty, a figure whose influence on Ireland was considerable and, depending on your perspective, deeply troubling. Petty was an English polymath, economist, and surveyor who arrived in Ireland in the mid-seventeenth century and became one of the principal architects of the Down Survey, the vast mapping project carried out in the 1650s that catalogued Irish land in the aftermath of the Cromwellian conquest, largely to facilitate its redistribution to English settlers and soldiers. He accumulated enormous landholdings in the process, particularly in County Kerry, and became enormously wealthy. His Dublin residence, as recorded by Somerville-Large in 1996, stood on what is now the north side of St Stephen's Green before the Shelbourne Hotel was built on the site. Nothing of the original structure survives.

The Shelbourne itself dominates that stretch of the Green today, so there is no question of stumbling across a ruin or a commemorative stone. What the site offers instead is a particular kind of historical layering that Dublin does well, where the city has simply built over its own past without ceremony. If you are in the area, the Green is freely accessible and worth a slow circuit, and the north side, where the hotel stands, gives some sense of how prime and central this patch of ground has always been. The absence of any physical remnant is, in its own way, the point. Petty shaped the map of Ireland more than almost anyone else of his era, and yet the place where he lived in the capital has vanished entirely beneath later ambition and later stone.