Pre-Bog Field Systems have become exposed as a result of peat cutting in“blanket bogs”, layers of peat covering large tracts of the landscape like a blanket. Many of the bogs would have formed in areas where trees were cleared for pasture and cultivation. A combination of wet climate conditions and soil degradation would have led to the formation of peat.
Radiocarbon dating has determined that blanket peat growth started as long ago as 6560 on parts of Valencia Island. In the vicinity of Glanlough which is a few miles from Staigue Fort House, there is a complex of pre-bog walls. Some of walls are composed of lines of boulders while others are low, stony banks. A number of small fields, rectangular in shape, can be discerned as well as a rough enclosure, 10.4m x 8.5m.