The arrangement is unusually orderly for such a remote and exposed location, which makes it all the more striking when you consider that it sits on ground described as marginal even by the standards of an already unforgiving coastline.

The system occupies a strip of the island's south-western end, roughly 1.2 kilometres long and 350 metres wide, concentrated between two deep sea coves, Fó Duilisc and Fó Tairbh. The fields extend north-west from the coast in a large, regular pattern, each one averaging around 160 metres by 65 metres, divided by stone walls that have accumulated across multiple periods of use. That phrase, multi-period, is significant: it suggests these boundaries were not laid down in a single act of planning but were modified, extended, and reworked by successive generations of islanders responding to the same hard ground. Within the system, one circular field, about 50 metres in diameter, contains a small centrally placed hut, just 4 metres across. A second hut, slightly larger at 5 metres by 4 metres, sits close to the cliff edge, which gives some sense of how fully the island's inhabitants pressed into its available space. Inishshark was finally evacuated in 1960, when its last remaining families were resettled on the mainland, and the fields have been untouched since.

The island is accessible only by boat and has no permanent facilities, but the field system rewards those who make the crossing. The ground between Fó Duilisc and Fó Tairbh gives a clear view of how the walls organise the landscape, and the circular field with its central hut is an unusual feature, the circular form being a relatively rare configuration within a largely rectilinear system.