Chungcheongbuk-do(Chungju-si)
Suanbo Hotspring is the first naturally yielded spring which originally started to flow 30,000 years ago. The sulphur spring is officially mentioned on the record during the 9th year of King Hyeonjong's reign (1018). It is also stated in the Joseon Dynasty’s authentic records, Donggukyeojiseungnam, Yeojido Map, Cheonggudo Map, Daedongyeojido Map and up to 30 historical books.The spring water was brought up deep beneath the ground (250m) with a temperature of 53°C and acidity level of 8.3. The alkaline water contains minerals such as lithium, calcium, natrium, fluorine, and magnesium that are healthful and refreshing.