About 21km (13 miles) southeast of Cheongju, this oncheon supposedly began spewing water over 30,000 years ago. It's officially mentioned on the record in 1018, during the ninth year of King Hyeongjong's reign. The water originates deep beneath the earth and has an average temperature of 127°F (53°C). Alkaline in nature, it contains such minerals as calcium, fluoride, lithium, sodium, and magnesium and is supposed to be good for your health. Now, it is a cozy spa resort with spas such as Suanbo Hi Spa (tel. 043/846-8898) and the Nakcheongtang (tel. 043/846-2905).