Sansuien is a hot spring ryokan located in Takajomachi, Kochi City, built on the former site of the lower residence of the Yamauchi family, the lords of the Tosa Domain. The grounds preserve the nationally designated Important Cultural Property, the Former Yamauchi Family Lower Residence Nagaya (long house), which conveys the history of the late Edo period to this day. The natural hot spring Suisaikaku is known as the only natural onsen in central Kochi City. The name Suisaikaku was given by the future Emperor Taisho when he was crown prince, and the calligraphy still displayed inside was brushed by Admiral Heihachiro Togo, who accompanied him. The water is a high-temperature sodium chloride spring with a source temperature of approximately 48 degrees Celsius. The salt content provides excellent heat retention and is known as the Bath of Heat and the Bath of Beauty. The bathing facilities include open-air baths, indoor baths, sauna, cascade bath, and cold water bath, allowing visitors to enjoy a famous hot spring while feeling the historic atmosphere of the castle town of Kochi.