Guanziling Hot Spring

Guanziling Hot Spring (關子嶺溫泉) is located in the mountainous Baihe District of Tainan, Taiwan, at an elevation of approximately 270 meters. It is one of Taiwan's "Four Great Hot Springs" (四大溫泉), alongside Beitou, Yangmingshan, and Sichongxi — a designation that derives from a 1916 Japanese guide to Taiwan's scenic and historic sites.

The hot spring was discovered in 1898 when a company of the Japanese 5th Infantry Battalion stationed at Chiayi, camped at the site of today's Hongye Park, came upon the thermal springs by chance. The first hot-spring inn, Yoshidaya (吉田屋, today's Jingle Hotel 靜樂館), opened in 1904. In 1913 a report by Government-General Research Institute staff that the water contained radium — then believed to be therapeutic — caused a sensation, and Chiayi Prefecture built a three-class public bathhouse that opened on December 14 of that year, after which the spring was styled "the foremost spirit spring under heaven" (天下第一靈泉). The area was further developed under Japanese rule with bathhouses, inns, and recreational facilities.

The spring water is a weakly alkaline carbonated type with temperatures reaching approximately 75°C. Its most distinctive characteristic is the high concentration of silt and mineral mud that gives the water a gray-black color and a uniquely slippery texture, earning it the designation as Taiwan's only "mud hot spring" (泥漿溫泉) and the nickname "black hot spring." The geological conditions of the area — clay-rich soil layers through which thermal water seeps — create this rare phenomenon. The area also features a remarkable natural curiosity: methane gas emerging from underground has been burning constantly for approximately three centuries, creating the famous "Fire and Water Spring" (水火同源).

During the Japanese colonial period, the area also saw the construction of a temple dedicated to Fudō Myōō (不動明王, Acalanātha) above the hot spring source in 1902, intended to pray for peace in the region. After the Japanese removed the original stone monument of the deity, local residents raised funds to rebuild the temple and recreate the statue, which became the present-day Huo Wangye Temple (火王爺廟).

Today, the Guanziling hot spring area retains elements of its Japanese-era character, including historic bathhouse architecture and the traditional resort atmosphere. Multiple hotels and public bathhouses continue to operate, making it one of southern Taiwan's most popular hot spring destinations. The area is accessible by bus from both Chiayi and Tainan, and the annual Guanziling Hot Spring Festival draws visitors from across the island.