A kistvaen or cistvaen is a tomb or burial chamber formed from flat stone slabs in a box-like shape.
The kistvaens were usually covered with a mound of earth and surrounded by a circle of small stones.
Kistvaens are also found associated with holy sites or burial places of early Celtic saints, who are often semi-legendary.
Saints associated with kistvaens include Callwen daughter of Brychan, Geraint,[2] Begnet,[3] and Melangell.
[4] Foundation remains of stone slab- or gable-shrines, or the cella memoriae of Mediterranean origin, may sometimes have been misunderstood in an earlier era of scholarship as a kistvaen, and the subject is complicated by this "woolly nomenclature.