The authors describe clay features dating from c. 34-23 000 years ago discovered in a stratified occupation sequence in a Greek cave. The clay was brought from outside the cave, puddled with water and shaped into shallow basins. Laboratory analyses have shown that these clay features were burnt. This together with the occurrence of fragments of wood ash and phytoliths lying on their surfaces suggest that these features were hearths used for cooking, including the roasting of wild grasses.