What is "conisterium"

A conisterium (or conisterion) was an apartment in Ancient Rome and Ancient Greece gymnasiums. It was where sand or dust was stored, for use by wrestlers after they had been anointed with oil. They would either sprinkle it on themselves, or a slave would do it. The purpose of this was so that during a fight, the oil or sweat would not prevent a wrestler from having a good grip on his opponent. Conisteriums were also found in palaestras. After a fight, or exercise, the powder was rubbed off with strigils, before the wrestler had a bath.