It measures roughly 21 metres across and stands 3.7 metres high, with a flattened summit platform about 6.8 metres in diameter. That flat top is the detail that tends to catch the eye of anyone who knows what to look for. Natural hillocks do not usually level off so tidily.

Mounds of this kind present something of a puzzle even to those who study them professionally. They may be prehistoric burial mounds, sometimes called barrows, which were constructed to cover the remains of the dead and to mark the landscape with a durable, visible statement of presence or territory. The relatively steep sides and levelled crown at Rossana are consistent with that tradition, though without excavation it is impossible to say with certainty what, if anything, lies beneath. What adds a further layer of interest is that another barrow sits roughly 120 metres to the south-west, suggesting this was not an isolated act of monument-building but part of a wider pattern of activity in the area. The mound occupies level ground that looks out over a gentle north-easterly slope dropping down towards a stream, the kind of setting that recurs in Irish prehistoric landscapes, where water and elevated sightlines seemed to carry some significance for the people who chose where to bury or commemorate their dead.