Dogo Onsen Honkan is the symbol of Dogo Onsen, said to be Japan's oldest hot spring with approximately 3,000 years of history. It is one of Japan's Three Ancient Hot Springs, alongside Arima Onsen in Hyogo and Shirahama Onsen in Wakayama. The hot spring appears in numerous historical texts including Nihon Shoki and The Tale of Genji. In 596 CE, Prince Shotoku visited and praised the area, saying it was like a heavenly paradise with its abundant camellias. The three-story wooden building, constructed in 1894, was designated as the first public bathhouse to be named an Important Cultural Property in 1994. Renovation work was conducted from 2019 to December 2024. The facility features Kami-no-Yu for casual bathing and Tama-no-Yu, an elegant bathhouse built in the Taisho era. Visitors can also view the Yushinden, Japan's only imperial bathhouse. The water is alkaline simple hot spring, drawn from 18 sources without heating or dilution, and is known as a beautifying bath with its smooth, colorless and transparent water.