The low, U-shaped mound at Ballyganner is a fulacht fia, a type of prehistoric cooking site found in considerable numbers across Ireland, typically Bronze Age in origin. The usual interpretation is that these were outdoor cooking places where water was heated by dropping fire-cracked stones into a trough, the debris from that process accumulating over time into the characteristic horseshoe-shaped mound of burnt and shattered stone that survives today.

This particular example sits within a large, multiperiod field system, suggesting a landscape that has been organised and worked across many centuries, with the fulacht fia representing one of its earliest readable features. The mound measures roughly 10.6 metres along its northeast to southwest axis and 6.5 metres across, rising only about 0.3 metres above the ground surface. Its opening faces southeast, and the two arms, southwest and northeast, are joined by a narrow connecting ridge roughly three metres wide, partly enclosing a small central area of around two and a half metres by one and a half metres. That enclosed hollow is likely where a wooden or stone-lined trough once sat, filled with water and heated stones.

The setting in the floor of the valley is characteristic. Fulachtaí fia are almost always found close to water, and low-lying, seasonally damp ground of exactly this kind would have provided both the necessary water source and the soft soil into which a trough could be cut. The surrounding field system gives the site a layered quality; the fulacht fia is only one element in a much longer story of people making use of this particular piece of Clare ground.