The Diaoyu Fortress or Diaoyucheng (simplified Chinese: 钓鱼城; traditional Chinese: 釣魚城; pinyin: Diàoyúchéng) is one of the great ancient battlefields of China, located on the Diaoyu Mountain in Heyang Town, Hechuan District, Chongqing. It is famous for its resistance to the Mongol armies in the latter half of the Song Dynasty. One of the most notable events was the death of Mongol leader Möngke Khan near the city, which forced the immediate withdrawal of Mongol troops from Syria and East Asia and prevented the Mongolian Empire from expanding towards Africa.