There are fire pools and smoke stoves in the scenic spot of the Great Wall. In ancient times, they were mainly used to provide information and alarm functions, but now they have collapsed and damaged. White ashes were found in the interior of the fire pool and in the kitchen door of the smoke cooker. Stones at the bottom of the fire pool, stones near the kitchen door of the smoke cooker can even be seen to have smoke and flames. Some of the pools and smoke cookers have been used.