Neandertal use of fire was very simple. Fireplaces were generally small and not surrounded by heat-retaining stones. However, a recent discovery by archaeologists Jean-Philippe Rigaud and Jan Simek at the SW French site of Grotte XVI have shed new light on the question of Neandertal use of fire. In a well preserved occupation level, they uncovered (and are still excavating) an enormous "combustion feature that covers nearly 20 square meters. It shows alternating bands of black, red and yellow that, for specialists in such matters, are keys to determining the temperature of the fire and its duration. According to the analyses undertaken by Rigaud, Simek and their colleague Thierry Guy, the fire at Grotte XVI was fueled by mosses and lichens from the surrounding cave floor and walls. Apparently it burned for a very short period, but at a relatively high temperature; and it was rekindled at least once. Although this appears to be a relatively simple use of fire, it raises a number of interesting questions: Were Neandertals able to create fire at will? What might have been the purpose of such short, hot fires? Why were more substantial fuels not used?