Seokbinggo (석빙고), designated as National Treasure No. 66, is one of the few remaining relics from the Banwolseong fortress in Gyeongju. It was used as an icehouse during the Joseon Dynasty. With three ventilation ducts and a floor angled to drain off the melting ice, it measures 2.4 meters wide, 1.78 meters high, and 18.8 meters long.