[China's Largest Tropical Volcanic Cold Spring] Jiuwentang Cold Spring in Hainan Province

● Longmen Town, Ding'an County, Hainan Province, China; ● Car required; Parking fee required; ● Plenty of restaurants and local products in the park; ● No ticket fee required; Jiuwentang Cold Springs is located in Jiuwentang Village, Longmen Town, Ding'an County, Hainan Province, China. It is 73 kilometers north of Haikou City and 32 kilometers east of Qionghai City. Two provincial highways connect to the East Line Expressway on Hainan Island, and the "Huangzhu" and "Qionghai" exits on the highway are 20 kilometers and 32 kilometers away, respectively. Jiuwentang Village is a late Pleistocene volcanic rock distribution area, characterized by a volcanic rock plateau topography formed by eruptions more than 10,000 years ago. The area is difficult to navigate because of the exposed volcanic rocks and the steep roads. The area located at the edge of the volcanic plateau has an elevation difference of about 10 meters, and the volcanic rock blocks are piled up to form the foreland landscape belt of the volcanic plateau. The lower part of this area is filled with layered volcanic peat, which is formed by volcanic lava covering the swamp. The peat is dark gray and thin in thickness. On the east side of the border of Daotian Ditch is a volcanic rock distribution area of ​​the Middle Pleistocene, formed about 700,000 years ago, and the surface layer has weathered and turned into red soil, forming two completely different landscapes. In the volcanic rock exposure areas of Ding'an Hanlin, Longhe, Lingkou, and Longmen Town, volcanic rock crevasses and holes are developed, but the continuity is low. Due to the abundant vegetation and infiltration of rainfall, the groundwater temperature does not change much, and the water temperature of the rainfall is retained. According to the naming standard for mineral springs, if the water temperature is over 32 degrees Celsius, it is called a "hot spring", and if it is below 25 degrees, it is called a "cold spring". In Hainan Island, a tropical region, the underground diving temperature is usually 27 degrees Celsius, but it has been newly discovered that the underground water temperature in the Jiuwentang area is below 25 degrees Celsius. The volcanic rock cold spring formed by discharging from the edge of the volcanic plateau is the largest volcanic cold spring in the country, with more than a dozen spring eyes and a daily natural flow of 40,000 cubic meters. The water of Jiuwentang volcanic cold spring is colorless and tasteless, transparent, and the temperature is 23℃-25℃ throughout the year. It is cool in summer and warm in winter, refreshing and delicious water, meeting the requirements of natural mineral water. It is a low-mineralized partial silicic acid cold spring, containing sodium, calcium and magnesium bicarbonate, and is rich in silica and germanium. Its health and nutritional functions are very high. Germanium promotes the production of antibodies, and has anti-tumor, anti-lipid peroxidation, anti-aging and other effects. Silica protects cell membranes, improves immunity, and prevents cardiovascular diseases and aging. Silicic acid softens blood vessels, contributing to the prevention and treatment of cardiovascular diseases and extending lifespan. The Jiuwentang Volcano Cold Spring flows gently, and small fish swim in groups of three or five. The area around the cold spring is rich in vegetation, with ancient trees towering, several large ginkgo trees forming their own forest, the fragrance of flowers and fruits in all seasons, and fresh, unpolluted air. The largest cold spring pool can accommodate 10 people.