Somewhere beneath the fields of Hobartstown in County Kildare, a cluster of circular and near-circular features lies invisible at ground level, detectable only from the air. Aerial photographs reveal cropmarks, the faint differential growth in vegetation that betrays buried archaeology below the soil, outlining a complex of four annular and penannular enclosures, meaning fully closed rings and incomplete or broken rings, with estimated diameters ranging from roughly 25 to 35 metres. Alongside these sits a single sub-rectangular enclosure measuring approximately 40 metres north to south and 60 metres east to west. The site is not marked by any visible monument; it exists, in practical terms, only as a pattern of darker and lighter crop growth visible on certain photographs taken from above.

The enclosures are considered likely candidates for ring-barrows or ring-ditches, two related but distinct prehistoric monument types. A ring-barrow typically consists of a low burial mound encircled by a ditch and outer bank, while a ring-ditch is the surviving trace of such a monument after centuries of ploughing have levelled the central mound, leaving only the encircling cut visible as a cropmark. Such features are commonly associated with Bronze Age funerary activity, though they can span a considerable chronological range. The photographs used to identify the Hobartstown complex were taken as part of the Cambridge University Collection of Aerial Photography, and the site does not stand alone in the landscape; several comparable sites have been recorded in the immediate vicinity, suggesting this part of Kildare may once have held a more extensive concentration of prehistoric ceremonial or burial activity than the present, unremarkable surface of the land would suggest.