The first crannog to be excavated in Argyll was the marine crannog of An Dòirlinn, Eriska (CANMORE ID 23328) (Munro 1885), though no artefacts were recovered and no other type of dating was possible at this early stage of archaeology. This site is unusual as it lies outside the two known concentrations of marine crannogs in the upper Clyde estuary and the Beauly Firth (Hale 2004), and it may be that others remain to be discovered on the Argyll coastline. The chance exposure of a crannog when Loch Glashan was drained as part of a hydro-electrical works, and later excavated by Jack Scott in 1960, led to the discovery of a range of organic material previously unrecorded, though unfortunately publication was delayed until recently (Crone and Campbell 2005). Re-assessment of the material led to the realisation by Batey that the leather 'jacket' described by Scott in fact was an early book satchel (see also Campbell 2010 for discussion). Leather-working seems to have been the main activity on this crannog, but E ware pottery and crucibles for fine metalworking link it directly to Dunadd (CANMORE ID 39564). An iron axe and a segmented silver-in-glass bead show contacts with the Norse world, rarely seen on mainland Argyll. Radiocarbon dates on the wooden objects from the site suggest a long period of occupation, though whether this was continuous or not is debateable, given the uncertainty over the taphonomic and decay processes within crannog structures (see discussion in Crone and Campbell 2005, 117-8). A survey of the crannogs of Loch Awe undertaken by Ian Morrison in the 1970s formed the basis of his influential book, Landscape with lake dwellings (1985), which investigated the relationship of the Loch Awe crannogs to the surrounding landscape, written from a geographer's perspective. No excavation took place during this survey, and only one radiocarbon date was obtained, which suggested an early Iron Age occupation at Ederline boathouse crannog (CANMORE ID 22775). Diving excavation has a long history in Argyll, with the Rev R J Mapleton undertaking one of the first diving explorations of a crannog in Britain at Loch Coille Bharr (CANMORE ID 39078) (Mapleton 1868). However, the only recent diving excavation has taken place at Ederline boathouse crannog, with both radiocarbon dates and finds of E ware indicating early medieval re-occupation of a site which was constructed in the early iron age and abandoned in the middle iron age (Cavers and Henderson 2005). These results, along with the Loch Glashan (CANMORE ID 40047) (Figure 97) evidence suggest that the crannogs, like the forts and duns, were intermittently occupied throughout the span of the first millennia, and it would be impossible to have excavation strategies which focussed on 'iron age' or 'early medieval' occupations.
Figure 97: Penannular brooch from Loch Glashan crannog, Argyll. Copper alloy with amber settings, 8/9th century, brooch diameter 34mm. © Ewan Campbell