The simplest shape of the fireplace was made of stones stacked up around a fire and is still familiar camping trips and cooking meals in a mess tin, and seems to have already appeared in the Stone Age because traces of it have been found in ancient structural remnants from that period.
もっとも単純な形の炉は、石を火の周囲に積み上げた物で、今日でもキャンプなどの飯盒による調理などでおなじみだが、既に石器時代にはそのような炉が登場していたと見られ、当時の遺構にその痕跡が見られる。