What draws archaeological attention to them is a detail recorded in 1872 that sets them apart from the more familiar category of lake dwelling: whoever built here apparently did so without using any wood at all.

A crannog, in the usual sense, is an artificial or semi-artificial island constructed in a lake, typically built up with layers of timber, brushwood, peat, and stone, and used as a defensive dwelling from the Bronze Age through to the early modern period. The structure at Loch Hoirbeaird fits that general outline only loosely. G. H. Kinahan, writing in 1872, described it as a "peculiar structure somewhat allied to a crannog, being wholly or in part an artificial island, but no wood appears to have been used in its construction." That absence is the curiosity. The overwhelming majority of known crannogs rely on organic material, particularly timber, to bind and build up the island platform, and it is usually that wood, preserved in the anaerobic lakebed mud, that survives and allows dating. A structure built entirely or largely from stone introduces a different set of questions about technique, period, and purpose. W. G. Wood-Martin, who catalogued Irish lake dwellings extensively in the 1890s, also noted the site, though neither he nor Kinahan examined it closely. Both recorded it from the shore.

The two islands remain heavily overgrown, and the site has not been subject to any recorded excavation or close inspection beyond those distant shoreline observations. Whether one or both of the islands represent the structure Kinahan described, and whether stone-only construction genuinely distinguishes it from other crannogs in the region, are questions that appear to remain open.