3Stout, Matthew. The Irish Ringfort. Dublin: Four Courts, 1997. 24.
The author states that "...the majority of Ireland's ringforts and crannogs were occupied and probably constructed during a three hundred year period from the beginning of the seventh-century to the end of the ninth-century AD." For his evidence he points out that the finds from ringforts usually include items that may be dated from the second half of the first millennium, such as certain pottery types (e.g. "souterrain ware") and ornamental beads and pins. The Garryduff bird is a beautiful example of a dateable find from a ringfort, c. 650 CE.