The feature is a fulacht fia, a type of site found in enormous numbers across the Irish countryside, typically consisting of a mound of fire-cracked stone alongside a trough that would once have been filled with water. The usual interpretation is that stones were heated in a fire, then dropped into the water-filled trough to bring it to a boil, most likely for cooking. Some researchers have proposed other uses, including fibre processing or bathing, though the cooking explanation remains the most widely accepted.

The Coolbane example is modest in scale, measuring roughly ten metres east to west and three to four metres north to south, and sits in tillage ground immediately to the north-west of a well. That proximity to a water source is entirely typical; fulachtaí fia are almost always found near streams, springs, or wells, since a reliable supply of water was the basic requirement for whatever activity took place at them. The site sits on a slope with a pronounced eastward aspect, which would have made it visible to anyone approaching from the valley below, though whether that had any practical or ritual significance is impossible to say from what survives at ground level.