The Diaoyu Fortress is one of the great ancient battlefields of China, located on the Diaoyu Mountain in Hechuan district, Chongqing.[Photo by Huang Jinguo/China Daily]

According to Yuan, the war only slightly changed the course of history, but fundamentally altered the development of the East. If Mongke had not died, his brother Kublai may not have become the Great Khan who ruled China, established the Yuan Dynasty in 1271 and built Dadu in modern-day Beijing, accelerating the fusion of different cultures and ethnic groups within east Asia.

Back in Chongqing's Hechuan district a 12.5-meter Buddha statue, one of the largest in China, sits among thousands of Buddhist grottoes, proving communication existed between China and India more than 1,000 years ago.

During World War II Chongqing was the temporary capital and a base for allied forces in Far East Asia. The Japanese bombed Hechuan nine times, killing hundreds of civilians.

A total of 35 million Chinese soldiers and civilians were killed and wounded in the war against Japanese invasion from 1937 to 1945. Their sacrifice helped prevent millions of Japanese troops from pouring into the Pacific to attack the Americans.

Lu Bo of Hechuan committee of the Communist Party of China, said people now understand something of the city's history and its place in the world. Rather than threatening historical sites, the district's healthy economy has financed their protection.

It was Chongqing that bore the brunt of the chaotic "cultural revolution" (1966-76). The local economy was destroyed as well as many antiquities, but the district, home to over 1.5 million people, is embracing new opportunities.

Ten years ago, Hechuan's primary industry was agriculture, a major center of pig breeding. It has now morphed into a major industrial base, with automobile, medical, and information industries.

Teng Ran, vice-president of Chongqing Hengxin Tianji Science and Technology, said the company has made products worth 5 billion yuan ($735 million) since it opened in Hechuan early this year. Its main product is a device which is carried into remote areas by drone and provides information on forest fires and other natural disasters. They are also working communication technology based on quantum encryption algorithms, he said.