At the end of the 19th century the architects David MacGibbon and Thomas Ross published their work on 'castellated and domestic architecture' and 'The ecclesiastical architecture of Scotland' which included black and white drawings and written descriptions revealing the condition of buildings at the time (MacGibbon and Ross 1887-92; MacGibbon and Ross 1897).
The work of the RCAHMS Inventories has probably been the most significant contribution to Argyll archaeology in the 20th century. The initial 1707 date restriction on RCAHMS survey work had been lifted in 1948 and so by the 1960s their remit included the 'more modern architecture'. There followed a series of seven volumes dealing with different geographical areas of Argyll with ever increasing detail and numbers of sites included. The first Argyll Inventory was published in 1971 and covered Kintyre, soon followed by Lorn in 1975 and Mull, Tiree, Coll and Northern Argyll in 1980 (RCAHMS 1971; RCAHMS 1975; RCAHMS 1980; RCAHMS 1982; RCAHMS 1984; RCAHMS 1988; RCAHMS 1992). The key words here are 'inventory', i.e. a list, and 'architecture' which deals with upstanding structures. The 'post-medieval' buildings were described from an architect's point of view and there was little concern about how they were used, how people moved around them or how buildings sat within the landscape. The buildings of the early modern period were dealt with in less than 15% of the gazetteer. Post-medieval alterations and re-use of medieval castles was highlighted in the RCAHMS volumes along with a summary of what was known historically.
These volumes brought together archive material, photography, plans and sections, aerial photography and written descriptions. The monuments were grouped as 'domestic architecture from the 17th to the 19th century', 'farms, townships and shielings', and 'industrial and engineering works including quarries'. This latter group contained a plethora of 19th and 20th century industrial and other buildings which are perhaps a surprise considering the rural nature of Argyll today. The industrial sites included blast furnaces, charcoal burning stances, gunpowder works, slate quarries, bridges, lighthouses, wells, distilleries, mills and illicit stills. In addition, there were descriptions of military roads, architectural fragments, carved stones and sundials, plus the burghs of Campbelltown and Oban and the town of Tobermory.
Because they were so numerous in the landscape, the deserted farms and townships were described only in general terms and were illustrated with a small number of examples. In the later Argyll volumes, the number of 'types' of sites increased to include kelp burning kilns, fish traps, harbours and piers. The final two volumes dealt with Mid-Argyll and the emphasis on the post-medieval period was greatly increased. This reflected the richness of Mid-Argyll (dominated as it is by Inveraray Castle, its estate and nearby town), but also a recognition that the later monuments were deserving of attention (RCAHMS 1992). However, by then the Inventory style was seen as 'impractical and out-moded' (Dalglish 2009, 234) and were replaced by a much more synthetic approach, as used in the first Perthshire volume (RCAHMS 1990).
The work of the RCAHMS did continue with the Argyll Castles volume which brought together all the documentary references and architectural details for each castle and a consideration of the later periods of their use (RCAHMS 1997). For example, Duntrune is an example of a castle that was built originally in the medieval period, and has been occupied, if not continuously, since then. There is a detailed description of the tower-house built within the castle in about 1600 for a member of the Campbell clan including alterations that took place in the later-18th and mid-20th centuries (RCAHMS 1992, 276-282). The historical records described how the castle had been garrisoned against Alastair MacColla in the 17th century and was used again during the 9th Earl of Argyll's rebellion. In 1796 the estate was acquired by Neil Malcolm of Poltalloch and undertook repairs and building works (Poltalloch Papers, Lochgilphead Archives). Duntrune remained the main house of the Malcolm's until the construction of Callton Mor (Poltalloch) in 1853, but when this large mansion house was abandoned in the 1950s, Duntrune was modernised and extended and remains in use as the Malcolm family home.