"No Tenyumoto Yukaisoukai Zama" is a day-use hot spring facility in Zama, Kanagawa Prefecture, that places great importance on the atmosphere of a traditional therapeutic bathhouse. The natural hot spring black water, which bubbles up from underground, is a mildly alkaline bicarbonate spring with a characteristically silky feel on the skin. In the open-air area, you can luxuriate in fresh, undiluted spring water flowing continuously from the source. The sauna is a large, five-tier tower-style sauna equipped with far-infrared heaters, allowing efficient sweating in a spacious setting. For cooling down after the sauna, there is a cold plunge bath fed by groundwater pumped up directly from underground, offering the smooth, gentle touch that only natural water can provide. You can also enjoy outdoor bathing in the open-air area, which offers a sense of freedom and lets both body and mind fully refresh.