Its entrance has been sealed since around 1920, and no trace of it survives at ground level. To all outward appearances, the field is simply a field.

The structure is a souterrain, an underground passage or chamber of the kind built throughout early medieval Ireland, typically as a place of refuge, storage, or concealment. This particular example is drystone-built, meaning its walls are constructed from stone laid without mortar, and it is roofed with flat lintels laid across the top. It runs on an east-west alignment and sits on gently sloping ground with a view towards the sea. When a man named O'Malley recorded it in 1937 for the Office of Public Works, he noted it simply as a "cave", which suggests that by that point its original character was either forgotten or deliberately understated. The entrance had already been blocked for roughly seventeen years by then, according to local information gathered at the time.