The earthwork at Cavanagarvan measures roughly 29 metres across at its widest, defined by a bank and an outer fosse, which is a defensive ditch dug around the perimeter to reinforce whatever barrier the bank itself presented. This kind of enclosure is broadly classified as a ringfort, one of the most common archaeological monument types in Ireland, though individual examples vary considerably in condition and character. What gives this one a certain quiet interest is its position and its layout: it crowns the summit of the ridge rather than sitting on a slope, and it preserves evidence of two separate entrances, each with its own causeway crossing the fosse.

The eastern entrance, which appears to have been the original, has a base width of five metres and was approached by a causeway standing roughly 0.7 metres high and three metres wide at the top. That entrance is now closed, meaning the bank has been built up or has slumped across the gap over time. A second entrance and causeway survive at the north-west. Along the eastern to south-eastern arc, the outer field bank appears to have been pushed into the fosse at some point, partially filling it, which suggests later agricultural interference with the monument's edge. The interior is grass-covered, and some bushes have established themselves along the bank. Drumlin country, with its rolling, whale-back hills of glacially deposited material, provided early settlement communities with naturally elevated and well-drained positions, and this ridge would have offered clear sightlines across the surrounding landscape in multiple directions.