It is estimated that there are between 30,000 and 40,000 forts (also named Lisses, Cahers of Fairy Forts) throughout Ireland. The simplest form is a circular ring of earth piled up as a bank and surrounded by a ditch of a number of concentric ramparts. In many of the forts are found underground artifical caves or souterrains, believed to have been store-houses or hiding places; many of these souterrains are elaborate structures with traps and puzzle passages.
In general, excavations have shown that these forts date from Bronze Age (circa 500-1100 BC.) to early Christian times. In spite of their names they are not all forts in a military sense, some where homesteads and cattle enclosures. Borrisokane can’t boast of having any Dolmens, stone circles Tumili, Cairns, Gallans or Crannogs, but we have many fine examples of Ringforts in the parish. Examples of forts can be found in Ballyhaden in N.E. of the town, Rathmore to the N.W. and in Lisheen, Aglish. With the intensification of farming, too many of these sites has vanished, but a lot of people believed in the myths and stories of the fairy fort and left them alone.