A small, partly or entirely man-made island, constructed to provide locations for shelters. Widespread in Ireland and Scotland from the early Iron Age until the C18th most crannogs have now turned (or returned) nature, and may only appear to be overgrown islets in lakes, rivers and estuaries.
Etymology
The Irish word crannóg derives from Old Irish crannóc, that referred to a wooden structure or vessel, stemming from crann, which means “tree”, plus a diminutive ending—literally “young tree”. The modern sense of the term first appears sometime around the 12th century; its popularity spread in the medieval period along with the terms isle, ylle, inis, eilean, oileán. There is some confusion on what the term crannog originally referred to, the structure atop the island or the island itself. The additional meanings of ‘crannog’ can be variously related as “structure/piece of wood; wooden pin; crow’s nest; pulpit; driver’s box on a coach and vessel/box/chest” for crannóg. The Scottish Gaelic form is crannag and has the additional meanings of “pulpit” and “churn”. Thus there is no real consensus on what the term crannog actually implies, although the modern adoption in the English language broadly refers to a partially or completely artificial islet that saw use from the prehistoric to the Post-Medieval period in Ireland and Scotland. [Wikipedia]