The 20th century saw a great increase in the level and range of work being undertaken in Argyll. However, archaeologists were still primarily concerned with the prehistoric and medieval periods. A field survey of archaeological monuments in Argyll by Marion Campbell of Kilberry and Mary Sandeman (Campbell and Sandeman 1961) described the many historic and prehistoric monuments, but there are also many additional comments on the later use of such sites. For example, there is a record that a cave at Tiretigan (CANMORE ID 70955) that had been used by outlawed MacGregors in the 17th century was 'recently' used by tramps and was known locally as the 'Frenchman's' or 'Smuggler's cave' which indicates a much more widespread use of caves in the modern period that might otherwise be acknowledged (ibid, 7). Campbell and Sandeman planned, but never published, a paper on the deserted settlements of the area, and so their archive (now held by Kilmartin House Museum) should contain much useful unpublished information on this topic.
Archaeological excavations on sites belonging to the early modern period were initially almost accidental, as the main aim of excavators was generally to reveal the earlier prehistoric deposits beneath. Exceptions to this include the excavations at Castle Sween (CANMORE ID 39028) (the earliest medieval castle in Argyll) where two phases of activity dating to the 16th to 20th centuries were recorded and it was noted that neither of these phases were reflected in the architectural fabric (Ewart and Triscott 1996). The presence of kilns, forges and associated buildings suggested that the site was used as a military depot rather than a lordly residence in the early 17th century (RCAHMS 1997, 90). The castle was abandoned in the mid-17th century after an attack by Alastair MacColla and it became overgrown, as discovered by MacGibbon and Ross in the early 19th century. A final 19th-and 20th-century phase involved clearance and consolidation works by the Ministry of Works, some detail of which might appear in the Ministry of Works records.
Only small scale excavations have taken place inside the 16th /17th tower house of Carnasserie Castle (CANMORE ID 22835) to allow for drainage works. This revealed little of significance (Murray 1998) despite it being garrisoned against Alastair MacColla in 1644, garrisoned again in 1685, burned in 1690 and left in ruins (RCAHMS 1992, 214-226). The castles of Argyll are famous and yet few have been excavated because of their Scheduled status.
An excavation was carried out in the 1960s at Eilean Dearg (CANMORE ID 40448), Kyles of Bute (RCAHMS 1992, 282-283) and revealed that the use of island refuges continued (mistakenly because of the increasing use of artillery) beyond the medieval period. This island was used to store gunpowder by the 9th Earl of Argyll during his rebellion in the 17th century and as a base for his fleet. The excavations retrieved numerous finds of 17th century date, including musket flints and balls, slate gaming counters, navigational dividers and 14th - 17th century pottery (Miller 1971). The remains provided evidence that the island had been blown up by government forces. Subsequently a timber dancing platform was erected on the island for the entertainment of Victorian steamship parties (Miller 1971, 578-9).
Archaeological excavations on industrial sites are also rare. Work was undertaken at the Bonawe furnace (CANMORE ID 23523) and at Glen Kinglass (CANMORE ID 23486) which revealed that both of these early modern enterprises were of varying success, which the excavator linked to climate change (Lewis 1984). Lewis suggested that the drought in the early 18th century was a possible contributing factor to the failure of some furnaces in Argyll. Research into charcoal burning platforms has been undertaken by Betty Rennie and others in order to show that 'the Lorn and Argyll furnaces were not responsible for denuding the Scottish hillsides of timber' in the mid-19th century (Lyndsay 1975; Rennie 1997). Rennie surveyed and mapped the sites and excavated about ten recessed platforms, some of which were shown to be originally prehistoric hut circles that had been reused as charcoal burning platforms. She included an assessment of charcoal burners practices and traditions and observed that the late-medieval technique of burning wood in pits was replaced by the above ground clamp kiln.
The Scottish Bloomeries Project involved an assessment of a late medieval bloomery and smithing hearth at Allt na Ceardaich (CANMORE ID 40845), Argyll. The study involved geophysics, topographic survey, excavation of the early ironworks and associated settlement and metallurgical analysis with the aim of characterising medieval and post-medieval bloomery technology in the Highlands (Atkinson 1996, Atkinson and Photos-Jones 1999).
Excavation of deserted rural settlements are also few in number despite these types of sites being numerous in the landscape. One example is an excavation on the island of Gunna (CANMORE ID 141630) (between Coll and Tiree) undertaken in 1998 (James 1998a and 1998b). The evidence suggests that the settlement dated from the late medieval to the 18th century when the island was under the control of the lairds of Coll and used for transhumance. The pottery assemblage included a particularly large collection of early modern hand-made pottery known as 'craggan ware' as well as glazed medieval pottery, mammal and fish bone. This site has unfortunately remained unpublished although the mammal bone is currently the subject of research at the University of Aberdeen.
As part of doctoral research into medieval settlement in Argyll two sites were excavated which turned out to date from the late-medieval and modern period, an 18th century lairds house at Glennan (CANMORE ID 152206) (James 2004b, 2005a, 2005b) and 17th century farmstead at Bàrr Mór (CANMORE ID 273094) (James 2004a). At Glennan near Ford, Kilmartin, the excavation revealed buildings with substantial stone foundations occupied in the 19th century in the vicinity of an 18th century lairds house. The place-name could be traced back to the medieval period but nothing of that date was found at this site.
The majority of recent archaeological work undertaken in Argyll has been prompted by commercial development responding to planning applications for windfarms, cemetery extensions and hydroelectric schemes (for example Ellis 2011a, Ellis 2011b, Lewis 2011) although not always uncovering any significant archaeology. Other professional surveys have responded to forestry schemes such as at Bridge of Orchy (Birch 2011a), the Isle of Ulva (Birch 2011b, Birch 2012), or other reasons eg Toward Lime kiln (Nisbet 2012) and Taynish Mill (Regan 2012). Excavations in 2015 at Tigh Mor, for the MacGregor Clan revealed a bloomery site which dates to the pre-1611 period (pers. comm. Peta Glew). Often post-medieval material is found while looking for archaeology of the earlier periods eg excavations at Ellan Vow (Baker 2012) and an aerial photographic survey of North Mull by the Morvern Maritime Centre (Martin 2012).
A reminder of the importance of shipping comes from the discovery of the wreck of the Swan (CANMORE ID 80637) and its excavation by Colin Martin. The ship had been sent by Oliver Cromwell in 1653 to attack Duart Castle (CANMORE ID 22662) on Mull, but had sank off Duart Point after a storm (Martin 2017).