Tengchong is one of China's three major geothermal areas, known as "Land Abounding in Geothermal Resources". A lot of springs of hot water and hot vapor are available here. Among of them, "Hot sea" which lies 20 kilometers away southwest of the county and in the center of the geothermal area is the most famous. Covering an area of 9 square kilometers, there are more than 80 springs of hot water and hot vapor, of which there are 14 springs whose temperature reaches 90℃. The spring can be regarded as a rarity as far as their number and geothermal energy are concerned.
Tengchong Hot Sea has been famous for many years. Xu Xiake, a famous geographical scholar of the Ming Dynasty (1368-1644), once wrote: "looking at the hot vapor from the distance, just like dense fogs rising from the mountain." Entering the scenic spot, walking along the road, there is the scientific research area, the hot spring entertainment pool, the Pearl Fountain, the Gumingquan, the Beauty Pool, and then is a big boiling pool with above 3 meters in diameter and a temperature of 97℃. The water here includes many minerals such as chlorine, calcium, magnesium, potassium, sulphur and so on which are beneficial to people's health, especially for the treatment to rheumatism, arthritis, skin disease.
The big boiling pot (Dagunguo)
The most magnificent view of the "hot sea" is the boiling pool with a temperature of 97℃. So it is called "the Big Boiling Pot" by the local people. It is above 3 meters in diameter and 1.5 meters deep. There are dozens of big springs of vapor with a temperature of 94℃ at the mouths of the springs, where you can steam food. There was a legend that once upon a time, an ox drank salty water of spring and dropped into it owing to its carefulness. When the shepherd boy turned back with villagers, the ox has already become beef. The two Chinese characters "热海" (Hot Sea) were carved on the stone standing 30 meters away from "the big boiling pot". There are some bathrooms and steam beds for people to take a steam bath or receive medical treatment
The Hamazui Fountain (Hama means toad, a small animal which looks like frog, and Zui means mouth)
Small path leads you to the Zaotang River, after passing through a section of stone stairs, little by little the Zaotang waterfall comes into view. The waterfall is not very big but the scenery around it is spectacular. On the left, a fountain looks like two frogs spraying out hot spring water, called The Hamazui Fountain by local people; while on the right, there is a fountain whose shape like the head of a lion, trickling hot spring water is dropping into the Zaotang River. Around the Zaotang River, fountains, hot springs, vapor springs are available here and there which make the whole gorge as a huge steam box.
There are many spectacular hot fountains in Zaotang River, among of which is a round fountain called Huataijing. There is a legend that the married woman would become pregnant if they drank the water of the fountain. Other spectacular sights include Gumingquan, Xiaogunguo, Yanjingquan and Pearl Spring, which is a pool of water with hundreds of spray holes in the bottom sending out pearl-like strings of hot bubbling water. All springs have a temperature of ９０℃. There are seven big hot fields located in Ruidian Township in the northwest of the Tengchong County. The hot fields are 1,000 meters long from south to north and 600 meters wide at the widest point. There are many points where hot water wells out, of which there are several dozens of big ones whose temperatures range between 40℃ and 95℃. By the Naxinjie Road, there is a hot water pond of over 3,000 square kilometers, which is formed by water gushing from the ground in great quantity. The hot fields are enveloped in mist, especially in the morning in winter and spring.