Hidden relics

In 1986, his neighbor sent him a helmet of a Japanese soldier, which brought back memories of the war.

"I decided to collect more items to help more people know the details of the Chinese people's fight against the Japanese, especially the younger generation," he said.

"I hope they can know how precious peace is, and remember their history."

At the time, Cao had achieved great success as a vegetable farmer.

"I still remember that the most I earned in a day was 2,000 yuan in 1983, which was unimaginable for most people at the time," he said. "Relying on my years of savings, I started my collecting journeys around the country."

In 1992, he moved to Suifenhe and settled at the foot of Tianchang Mountain where an important Japanese army garrison had been located.

Even though the garrison had been completely destroyed by artillery fire, some remains of it can be found in the forest.

In 2000, a friend told Cao about some war memorabilia that might be available in East China's Fujian province.

He spent several months traveling to different cities and counties in the province, such as Zhangzhou and Dongshan, where he collected more than 100 pieces, including gas masks, military blankets and uniforms.

"I only took 2,000 yuan and it was not enough to pay for all of it," he said. "To earn money, I found a short-term job making dumplings at a local restaurant."

He spent all his money on the items, and did not have enough funds to pay for the excess baggage on his return trip. "I thought I must keep all the precious relics, so I threw all my clothes away," he said.