Aerial photography and excavations have brought to notice a major prehistoric ceremonial complex in central Scotland comparable to Stonehenge, although largely built in earth and timber. Beginning, like Stonehenge, as a cremation cemetery, it launched its monumentality by means of an immense circle of tree trunks, and developed it with smaller circles of posts and an earth bank (henge). A change of political mood in the Early Bronze Age is marked by one of Scotland's best preserved dagger-burials in a stone cist with an engraved lid. The perishable (or reusable) materials meant that this great centre lay for millennia under ploughed fields, until it was adopted, by design or by chance, as a centre of the Pictish kings.