What is verified
McCaig’s Tower was already a prominent landmark before the First World War. National heritage archives include twentieth-century photographs and aerial views, while Oban War & Peace Museum preserves material relating to the town in wartime and peacetime.
Oban’s wider wartime story included naval activity, coastal defence and flying-boat operations. The accredited Oban War & Peace Museum is the appropriate specialist source for that local history.
What is not yet verified
The credible designation, national heritage and academic sources reviewed for this website do not document the tower as a formal observation post, gun position, air-raid facility or military headquarters. Such claims should not be repeated as fact without a dated archival record or museum catalogue reference.
How to research the question further
Researchers should consult Oban War & Peace Museum, local newspapers, council archives and the National Record of the Historic Environment. A wartime photograph showing the tower in the background proves that the landmark existed in the scene; it does not by itself prove military use.