The site is a rath, the Irish term for a ringfort, which was the standard form of rural farmstead throughout early medieval Ireland, roughly from the fifth to the twelfth century. Most were the homes of farming families of moderate status, defined by a circular earthen bank that offered a degree of privacy and security for livestock and household alike. This one at Tullig is modest in scale, measuring around 22 metres in diameter, but it survives with enough clarity to read in the landscape.

The enclosure sits on a break in an east-facing slope, a position that would have offered both drainage and a view down towards the river below. To the south-east, the defining scarp still rises to about 1.4 metres, which gives a reasonable sense of the original earthwork. Elsewhere around the circuit, the bank has reduced to a gentle grassy swell of roughly 0.4 metres, barely distinguishable from the surrounding field. A shallow depression running from the north-north-west to the north-east, just outside the bank, is thought to be the remnant of an external fosse, the ditch that would originally have accompanied the raised bank. The combination of bank and fosse was the typical ringfort arrangement, with the upcast from the ditch piled inward to heighten the enclosure.