A rare radium- and iodine-rich hot spring and a Showa-strong sauna
Miyazaki Shintomi Town
Shintomi Town Onsen Health Center Sun Lupinus in Shintomi Town, Miyazaki Prefecture is a public bathhouse deeply loved by locals. It prides itself on a rare, free-flowing natural hot spring source rich in radium and iodine, said to help relieve fatigue and improve skin. The sauna is a Showa-strong style using an Olympia far-infrared gas heater and exceeds 100℃. A local custom remains of wiping your sweat with the bath towel provided in the sauna before leaving, and the cold plunge bath uses continuously running fresh water so you can enjoy seasonal variations in temperature.
TypeNatural Hot Spring
Iodine-sodium-chloride spring (neutral). Unusually for Kyushu, a free-flowing natural hot spring rich in radium and iodine is offered here. In the large communal bath and the airy open-air bath, you can fully enjoy this high-quality hot spring that warms you to the core.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity8people
A Showa-strong style sauna set to 100℃, anchored by an Olympia far-infrared gas heater. The compact space distributes intense heat that warms you deeply. A local etiquette of wiping the seat where you sat with a towel before leaving helps keep the room clean.
Water QualityTap Water
Capacity2people
A compact cold plunge bath for 1-2 people located right next to the sauna. Fresh water runs continuously from the tap, keeping water quality high. The water temperature varies by season, icy cold in winter and pleasantly milder in summer.
Closed Days: None
1859-1 Minashiro, Shintomi, Koyu District, Miyazaki 889-1402, Japan
Gender Access
Gender Separated
Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more
A rare radium- and iodine-rich hot spring and a Showa-strong sauna
Miyazaki Shintomi Town
Shintomi Town Onsen Health Center Sun Lupinus in Shintomi Town, Miyazaki Prefecture is a public bathhouse deeply loved by locals. It prides itself on a rare, free-flowing natural hot spring source rich in radium and iodine, said to help relieve fatigue and improve skin. The sauna is a Showa-strong style using an Olympia far-infrared gas heater and exceeds 100℃. A local custom remains of wiping your sweat with the bath towel provided in the sauna before leaving, and the cold plunge bath uses continuously running fresh water so you can enjoy seasonal variations in temperature.
TypeNatural Hot Spring
Iodine-sodium-chloride spring (neutral). Unusually for Kyushu, a free-flowing natural hot spring rich in radium and iodine is offered here. In the large communal bath and the airy open-air bath, you can fully enjoy this high-quality hot spring that warms you to the core.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity8people
A Showa-strong style sauna set to 100℃, anchored by an Olympia far-infrared gas heater. The compact space distributes intense heat that warms you deeply. A local etiquette of wiping the seat where you sat with a towel before leaving helps keep the room clean.
Water QualityTap Water
Capacity2people
A compact cold plunge bath for 1-2 people located right next to the sauna. Fresh water runs continuously from the tap, keeping water quality high. The water temperature varies by season, icy cold in winter and pleasantly milder in summer.
Closed Days: None
1859-1 Minashiro, Shintomi, Koyu District, Miyazaki 889-1402, Japan
Gender Access
Gender Separated
Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more