Current evidence suggests that artificial island dwellings were first built in the area in the Early Iron Age and of the 29 recorded examples, surviving either as partially or completely submerged, the densest distribution is around the shores of Loch Tay. In most cases, the preservation of organic material is exceptional and structural timbers have been noted protruding from the stony mounds or on the loch bed around them, with further structural and artefactual material surviving within the mounds. Not all can be dated to the Iron Age but higher precision dating carried out in recent years has pinned crannog construction across Scotland, including Perth and Kinross, to no earlier than 600 BC (Cook et al forthcoming). While research has shown that the majority of Scotland’s crannogs have Iron Age origins (Crone 2012), some do appear to be solely early medieval, medieval or post-medieval in date, such as Council Island in Loch Treig, Highland. As discussed in the early medieval chapter, this may be the case with some Perth and Kinross sites, such as Castle Island in Loch of Clunie (MPK5255) or the Loch Beanie Crannog (MPK4235) but equally, earlier Iron Age origins for these sites cannot be ruled out without closer investigation and dating.
Oakbank is the most extensively excavated underwater crannog in Scotland (MPK484; Dixon 1981; 2004). Work there, which has been ongoing periodically since 1980, recovered numerous unparalleled wooden artefacts and exceptional evidence for Iron Age life. New work, which began in 2017 as part of the Living on Water project, has significantly improved the chronological security of the initial Iron Age emergence of crannogs, including at Oakbank (see Oakbank Crannog Case Study). This period in the Early Iron Age has been described by Cavers as the crannog ‘event horizon’ in Scotland (2006). In Perth and Kinross, only Loch Tay has been intensively surveyed for crannogs, with minor survey and dating programmes in other lochs in the region (Dixon and Shelley 2006). There is therefore great potential for the discovery of more sites; given their unique preservation conditions, it is difficult to understate the role crannogs can play in informing understanding of Iron Age life and economy.
In conclusion, the area includes diverse and complex variation of settlement forms and in the past analysis has largely been based on morphology. Technical advances may help to reveal potential explanations for diversity, through improved chronological resolution (eg the Living on Water project), exploring expressions of identity in architecture (eg Romankiewicz 2009, 2011, 2016; Cavers et al 2016; Barber 2017). Other potential reasons for diversity include resource availability impacting the design of the crannog (Strachan 2013) and the impact of later land use on survival (eg Historic Land Use Assessment). Ultimately, however, more excavation is required to better understand architectural diversity (Davies 2006, 150).
