Over these centuries, the city's relics suffered numerous assaults. In the 13th century, Mongol forces destroyed a nine-story wooden pagoda at Hwangnyongsa. During the Imjin War (1592–1598), the Gyeongju area became a heated battlefield and Japanese forces burned the wooden structures at Bulguksa. Not all damage was due to invasions, however. In the early Joseon period, a great deal of damage was done to Buddhist sculptures on Namsan by Neo-Confucian radicals, who hacked arms and heads off statuary.