The mound is roughly eighteen metres across in both directions and rises to about 2.2 metres, which is a considerable presence in an otherwise flat agricultural setting. A gap of 3.5 metres faces south, forming the characteristic opening of the horseshoe, though a cattle track has cut through the base of the arms where they flare outward, separating them from the main body of the mound.

What the mound is made of is what makes it strange: the entire mass consists of burnt and heat-shattered stone. This is a fulacht fia, a type of prehistoric cooking site found in enormous numbers across Ireland, most dating to the Bronze Age. The basic method involved heating stones in a fire, then dropping them into a water-filled trough to bring the water to a boil. The stones crack and crumble with repeated use, and over time the discarded fragments accumulate into exactly the kind of dark, charcoal-flecked mound visible at Sraharla. The proximity to a natural spring was not incidental; a reliable water source was essential to the whole operation, and many fulachtaí fia are found precisely in low-lying, wet ground where springs or streams were close to hand. The horseshoe shape itself is typical, the hollow centre of the curve often marking the original position of the trough.