A series of raised, roughly rectangular platforms, each around 50 metres long and 30 metres wide, push up through the grass, separated by wide, shallow sunken ways. Rock outcrops interrupt the surface, and irregular ditches, visible on Ordnance Survey maps as far back as 1937, trace lines that archaeologists have interpreted as the outer defences of what was once a functioning medieval community. The fragmentary remains of Carrickmines Castle, since absorbed into farm outbuildings, sit at the centre of all this, and it is around and beyond the castle that the evidence for a deserted settlement begins to accumulate.

The site sits in the townland of Carrickmines Great, known in Irish as Carraig Mhaighin Mhór, in the parish of Tully in the barony of Rathdown. Excavations carried out in connection with the M50 south-eastern motorway scheme, and reported in detail by T. Breen in 2012, revealed a double fosse and double bank along the north-western flank of the site; a fosse, in this context, is a defensive ditch, often accompanying an earthen bank. A stone-revetted fosse to the south-east was interpreted as part of a curtain wall, enclosing an angular area connected to an earlier enclosure by a causeway. Two further linear fosses roughly 60 metres south of the castle may mark an outer defensive perimeter. Among the finds recovered were considerable quantities of late 13th and early 14th century pottery, including Saintonge ware, a glazed ceramic produced in the Saintonge region of south-western France and widely traded across medieval Europe. Alongside it came an iron axehead, spindle whorls used in spinning thread, leather shoes, rotary querns for grinding grain, iron keys, and various buckles and nails. A cobbled surface, a millpond, a kiln, and wells were also uncovered, suggesting a settlement with its own productive infrastructure rather than a simple cluster of dwellings. A survey note from July 1996 speculated that a fosse at the junction of two streams could have served as the leat, or water channel, supplying a mill.

The site is recorded in the 1998 Record of Monuments and Places for County Dublin and lies on low-lying terrain accessible from the Golden Ball-Carrickmines Road. The earthworks are most legible from ground level in low winter light, when the shadows thrown by the raised platforms and sunken ways between them become easier to read. The castle fabric itself has been incorporated into agricultural buildings, so there is little masonry to observe above ground; the interest here lies in the landscape rather than standing structures. John Rocque's 1760 map of County Dublin shows a cluster of dwellings on the south side of the river at Carrickmines, a reminder that this was a place of some local significance long after the medieval period had ended.