To give a modern analogy, Mingary was like taking one of the Royal Navy's new Type 45 destroyers and sitting it next to the M8 motorway; and Mingary's version of highway patrol cars would have been small, fast ships that were pulled up on the beaches on either side of the castle, ready for immediate launch if a passing vessel required intercepting. Mingary therefore dominated the sea out as far as the islands of Tiree, Coll and Eigg.
As well as being a fighting machine, Mingary was a statement of power. Today, the stone of the curtain walls blend in to the landscape, but we know from recent archaeological work that the outsides of the walls were harled, and that their colour was a slightly pink shade of white. Like a lighthouse, the castle would have been visible from miles away, and its statement would have been that no-one passes the Sound of Mull without Mingary's permission.
In our modern system of routes, Mingary is way off the beaten track, stuck out at the end of a long peninsula, far from the modern nodes of settlement and transport. Some of the castle's importance therefore lies in its very neglect, with the result that much of its original structure is still there and visible. That it became so remote had another benefit: it wasn't changed, so it remains a iconic example of Gaelic architecture uninfluenced by Norman, English or other outside ideas.
While it was probably built by the MacDougalls, Mingary became one of a chain of castles in the Lordship of the Isles, part of the great MacDonald fiefdom, and the seat of one of Clan MacDonald's most important and powerful septs, Clan MacIain. The Lordship was almost a kingdom in its own right, for it often operated outside the jurisdiction of the Scottish king.
Remote, little known, it would have been so easy to allow Mingary to collapse into a picturesque ruin. That work has now started to rescue it is thanks to the efforts of the man who owns the Ardnamurchan Estate and Mingary itself, Donald Houston, who has set up the Mingary Castle Preservation & Restoration Trust. The Trust faces a huge task, not least in researching and recording before the work of stabilising and preservation can begin. An appeal for funds will be launched shortly, and it is hoped that people from all over the world will join together in helping to preserve this wonderful piece of Scottish history.
Many thanks to Addyman Archaeology for background information & advice.