A pit circle is a ring or arc of more or less discrete oval-shaped holes which were dug and back-filled within a fairly short time and which enclose a round area of flat ground. Pit circles are typically between 10m and 20m in external diameter. Some may originally have had low banks or piles of upcast immediately inside the ring of pits, and there may also be upright posts set in the pits or within the circle. Most are recognized in the first instance through aerial photography or excavation; none are known as earthworks.
Pit circles are sometimes confused with the segmented ditches around some types of hengiform monuments and with segmented ring-ditches around some types of bowl barrows. Excavation is often required to resolve such confusions, but, in general, hengiform monuments involve larger and less discrete pits while segmented ring-ditches generally have fewer segments than pit circles have pits. Since pit circles sometimes represent primary phases within multi-period monuments their presence as seemingly integral parts of other sites should occasion no surprise. Other possible sources of confusion are with posthole settings such as those found in timber circles, forming enclosures around the central burial in some types of bowl barrow, or as structural components of buildings of any date from later prehistoric times through to the post medieval period.
Specifically excluded from this definition of pit circles are the rings of pits forming components of other classes of monuments, for example rings of postholes and stone sockets found within henges and enclosed cemeteries.
Pit circles are generally interpreted as burial/ceremonial monuments of Neolithic date, and as such their function may have overlapped with that of other contemporary monuments.