Ringforts or ring forts are small circular fortified settlements built during the Bronze Age, Iron Age and early Middle Ages up to about the year 1000 AD. They are found in Northern Europe, especially in Ireland. There are also many in South Wales and in Cornwall, where they are called rounds. Ringforts come in many sizes and may be made of stone or earth. Earthen ringforts would have been marked by a circular rampart, often with a stakewall. Both stone and earthen ringforts would generally have had at least one building inside.
The ringfort at Rathrar in County Roscommon, Ireland
Ringfort on the island of Inishmaan, Aran Islands, Ireland
Caher on Black Head, County Clare, with karst terrain in foreground
A typical ringfort incorporated into field boundaries in County Tyrone, Northern Ireland
Souterrain is a name given by archaeologists to a type of underground structure associated mainly with the European Atlantic Iron Age.
Neolithic souterrain on Canna Island, Hebrides
Panoramic view of a souterrain contemporary with a ringfort dating to around 700 AD, built within a much earlier barrow cemetery, in County Armagh, Northern Ireland
Plan and sections of an earth-house at Kildrummy, Aberdeenshire