A massive folly on Battery Hill overlooking Oban, McCaig's Tower forms a prominent landmark which was commissioned by John Stuart McCaig (1823 - 1902), a local banker. Built in the style of the Roman Colosseum and comprising two tiers of pointed arches built in granite and arranged in a circle c.63m (206 feet) in diameter, the folly serves as a memorial to McCaig himself and his family. The height of the walls varies with the topography of the summit. Entrance is through a castellated bay which is higher than the remainder of the structure and features a plaque, with the following inscription:
"Erected in 1900 by John Stuart McCaig, art critic and philosophical essayist and banker, Oban"
McCaig promoted the project to employ local stone-masons who were without work during the winter months. It was therefore during these months only when construction was undertaken between 1895 and 1902. McCaig had planned a more elaborate structure, with an internal tower containing a museum and art gallery, but his death brought an end to the money and the construction stopped with only the outer walls completed. It is now B-listed.