It is built of Bonawe granite taken from the quarries across Airds Bay, on Loch Etive, from Muckairn, with a circumference of about 200 metres (660 ft) with two-tiers of 94 lancet arches (44 on the bottom and 50 on top).
The structure was commissioned, at a cost of £5,000 sterling (equivalent to £690,000 in 2023[4]), by the wealthy, philanthropic banker (North of Scotland Bank), John Stuart McCaig.
[5] The tower was erected between 1897 and his death, aged 78 from cardiac arrest, on 29 June 1902 at John Square House in Oban.
McCaig was an admirer of Roman and Greek architecture, and had planned for an elaborate structure, based on the Colosseum in Rome.
[11] Also reported in the Oban Times drinking of alcohol is prohibited in the tower under local by-laws.