Ringforts, known in Irish as raths or lios, were the most common form of rural settlement in early medieval Ireland, typically dating from roughly the sixth to the twelfth centuries. A farmer or minor lord would enclose a homestead within one or more earthen banks and ditches, less for military defence than for the demarcation of property and the management of livestock. The lios element in the townland name Lislea almost certainly derives directly from this structure, meaning that the fort has shaped local nomenclature for long enough that the name outlasted any memory of who built it.

Beyond the townland name and the classification itself, documented detail about this particular site remains sparse. What can be said is that Galway's landscape contains hundreds of these monuments in varying states of preservation, some reduced to a faint circular cropmark visible only from the air, others still carrying substantial banks that alter the feel of the ground around them. The presence of one at Lislea places the townland within a pattern of early medieval land use that was once distributed across virtually every fertile corner of the country.