A large irregular stone circle is a prehistoric ritual or ceremonial monument comprising a ring-shaped setting of at least 20 stone pillars, each less than 0.8m high, which are, or were once, set upright. The diameter of recorded large irregular stone circles varies from 20m to 40m, although there are several larger examples. The pillars are closely spaced and are not apparently graded in height. Other components which may be present are outlying standing stones, centre stones, portal stones, inner cairns, banks around the circle and internal stone features.
Large irregular stone circles may be confused with large regular stone circles, however the megaliths in such circles are generally taller and more evenly spaced and in plan form a neo-geometrically perfect circle. Large irregular stone circles are easily distinguished from small stone circles, because the latter have a diameter less than 20m.
Different types of large irregular stone circles may have served different functions. The plain circle which consisted only of the ring of stones with no apparent associated features may have served as meeting places for the community whereas the embanked circles which generally occur in conjunction with an inner cairn seem to have had a sepulchral function. The excavated cairns invariably produce urns. The monument class was probably current from the Late Neolithic to the end of the Early Bronze Age, broadly speaking the late third and early second millennia RCYBC.