On a range of the Ailao Mountain stands a ancient town named Yisa which was known for its prosperity in as early as the beginning of 20th century and called the Small Hong Kong outside the River. The Yisa Town, 260 kilometers far from Kunming and 150 kilometers far from the seat of the Mengzi Prefecture, is the political, economic and cultural center of the Honghe County and one of the three overseas hometowns of the Yunnan Province. Yisa means “the place which is dry and lacks water.” The township currently still has about 100 ancient folk houses. In as early as the end of the Qing Dynasty, the enterprising people of the Yisa Town had started building “horse roads” to countries of the Southeast Asia, and after working hard successively for 100 years, they ultimately completed 11 “horse roads” and started a new era for trades between the Yunnan Province and these countries. From this town, hardworking and wise people constructed the first road to the Southeast Asia. From this town, the people went out and became the first batch of overseas Chinese. 

The people of this town also built up the town into a prosperous place integrating both Chinese western cultures and the horse column characters. The horse trade was the career of the people of the Honghe County. Since the countries of the Southeast Asia were French and English colonies and affected by the western culture, the horse column traders also brought western architectural characters into this town. They transported bricks, tiles and lumbers to the town from other places and constructed many mixed-style castle buildings. The Yisa Town was actually like a European-style town with Chinese characters. It is known as the “Hometown of Overseas Chinese in the Yunnan Province” and also the “Architectural Showplace outside the River.” Behind the two titles are two miserable periods of history.

In the Qianlong Emperor and Daoguang Emperor period of the Qing Dynasty, the copper smelting industry thrived in the Yisa Town. The industry attracted a lot of Han nationality people to this place and they brought in advanced copper smelting techniques and business management skills which promoted the prosperities of various industries in this town. However, due to the long-term lumbering and excessive exploitation, the hills became bald, the environment was ruined and the water resource was more lacking. By the end of the Qing Dynasty, many copper mines were closed due to various reasons. Therefore, the miners who had lost their jobs formed horse columns and started doing the trade business in countries such as Laos, Vietnam, Burma and Thailand. Because of the wide plain of the Southeast Asia, the traders called their business “going to the plain.” Sometimes they traded opium, but they usually traded gold, silver, medical materials, salt and other products.