In many ways, Spa LaQua feels more like a ‘super sento’ than an onsen. This hot-spring complex within Tokyo Dome City uses sodium chloride-enriched hot-spring water. This gushes out from 1,700m underground. Also, the water is said to help in healing colds, muscle stiffness and neuralgia. Enjoy indoor and open-air baths or a low-temperature sauna, which filters its steam through stones such as tourmaline, loess, elvan and germanium. Thanks to far infrared rays and negative ions, blood circulation, metabolism and waste removal is accelerated. If you’re a sucker for pampering, then you can visit the beauty salon. To add, you may get a Thai or Hawaiian massage with body scrubbing.