These islands possess a number of Midden sites though they remain undated as yet. Possibly the earliest remains of human habitation on the islands were evident in the sandhills opposite Inishlyon in the town land of Knock. During the Clare Island Survey of 1911-1914, it was noted that these middens contained charcoal, peat quantities of limpets, periwinkles, oysters, mussels and broken bones. A hammer stone was also found at the same position. This hints at a possible early date for these sites. However, these middens are almost non-existent today due to coastal erosion and intensive rabbit habitation. Other sites have been identified in Braid at the south end of the Harbour.
The Neolithic Period
Despite the apparent absence of Mesolithic and Neolithic sites it is clear from analysis of lake sediments that Neolithic sites communities had an impact on the landscape of these islands. The presence of a saddle quern in the town-land of Knock provides sound archaeological evidence in support of the sediment analysis results.
The field systems that were uncovered in the more marginal and rough land of Bofin may date from the Neolithic to Medieval times. These consist of a profusion of substantial house sites with coeval field systems, terraces and fulachta fiadha. Two of the more important settlement complexes are located on the south side of Inishlyon and the north shore of Inishark. Those and the site in West Quarter are pre-bog sites and suggest an older period than others on the island. The field systems located at Middle Quarter, Knock hill and Bunamullan suggest intensive farming and a large population.
The ancient stone terraces are thought to be of Bronze age origin. The widespread distribution of these terraces, house sites and fulachta fiadha point to a huge expansion of population during the late Bronze Age which may have led to marginal areas being taken in to cultivation. This in turn may have resulted in the exhaustion of the island’s more fragile soils, to their abandonment and subsequent envelopment in peat.
Coastal Promontory Forts thought to be of The Iron Age are common on these islands, the most dramatic been Dun Mor in West Quarter. This fort “consists of a wall of masonry, curving around a natural terrace, half way up the slope of the headland with several hut sites around the low hill eastwards from the Dun”. The rubble from the original defence wall is still visible. Such forts were built for defence purposes along the cliff edge with a complete view of the surrounding water.
There are at least 3 others on Inishbofin, Dun na h-Inine, Dun Dubh, and Dun Graine. The latter is said to have been occupied by Graine Uaile who from there defended the entrance of the harbour against intruders. The discovery of a medieval window fragment on this site recently provides us with the sole surviving artefact of this long lost O’Maille Castle.