It was a small discovery, made sometime in the 1940s, but its implications were considerable: evidence that iron-working, a skilled and demanding craft, had been carried out on this island at some point in the past. What makes the site quietly puzzling is not what was found but what cannot now be located. The slag has not been recovered since, and the exact spot of the original discovery remains unknown.

The name Friars Garden points towards a monastic connection, and island sites along the lakes and rivers of Leitrim were frequently chosen by early medieval religious communities who valued their relative seclusion. Iron-working in such contexts was not unusual. Monasteries across early medieval Ireland maintained smiths who produced tools, fittings, and implements, and the craft carried a certain prestige. Slag, being heavy and inert, tends to survive well in the ground, which makes its absence on subsequent inspection more notable rather than less. Whether the original material was removed, disturbed, or simply lies undisturbed in an unexamined corner of the garden is a question the site has so far declined to answer.