A timber circle is the foundation of a large wooden structure comprising a series of two or more roughly concentric rings of postholes which once supported substantial timber uprights variously interpreted as stanchions of a roofed building or freestanding posts. Timber circles are generally over 20m in diameter and the individual postholes are typically over 0.5m across. Timber circles are found as discrete monuments and as components of henges and henge-enclosures; only the former are discussed in detail here. All known examples have been discovered through aerial photography, excavation, or geophysical survey; none are known as earthworks.
Timber circles are most often confused with pit circles or with stake circles forming components of some types of bowl barrows. Pit circles can usually be differentiated because they are smaller in overall diameter than timber circles, have larger pits, did not necessarily have posts set in all the pits, and only have one ring of pits. Stake circles are also generally smaller than timber circles, and are usually distinguished by the small size of the postholes/stakeholes. Other sources of confusion include the remains of circular buildings of later prehistoric date, and tree planting circles of very recent date (see Bradley & Mead 1985). Close attention to size, arrangement and relationships is needed to distinguish these monuments from timber circles.
Specifically excluded from the definition of timber circles are the rings or arcs of postholes found within or around henges which form a component of that class, and the posthole arrangements of domestic buildings.
Timber circles are generally interpreted as the remains of large buildings which served a public or communal purpose, perhaps as meeting places or ceremonial centres, during late Neolithic times.