Stone Forts are a common element of the archaeological remains in the west of Ireland. Most are equivalent to the earthen ringforts found throughout the country and were probably built as homesteads during the period 500 - 800AD - these stone ringforts are called cashels. However a number of stone forts stand out from the remainder either because of their large size or their prominent locations or because they have complex or massive defensive features. A good example of one of these larger stone forts is Staigue Fort in Co. Kerry. Stone Forts represent the best examples of non-ecclesiastical monumental architecture which survives in Ireland from the pre-Norman period.
Ring Forts were enclosed farmsteads in the Early Christian/Early Medieval period. Ringforts are circular areas, measuring c.24-60m in diameter, usually enclosed with one or more earthen bank enclosures, often topped with a timber palisade. In the west of Ireland the ringfort equivalent, the cashel, was often enclosed by a stone wall, with stone huts in the interior. The inhabitants were largely self sufficient, and it is not uncommon to have neighbouring ringforts, some of which may have may have served as an early medieval livestock pen.
Souterrains are often associated with ringforts and also date to the Early Medieval period. The term souterrain derives from the French words sous, meaning under and terre, meaning ground. Souterrains are sub-terrain man-made structures consisting of chambers connected by creepways and with access to the surface. Souterrains may be constructed using different materials such as stone and wood and may be tunnelled into rock or utilise a natural cave. They are variously interpreted as places of refuge or storage areas and generally date to the later phase of the Early Medieval period (eighth/ninth century A.D.).