This popular spa chain has branches all over Bangkok (and the rest of the country), but the one in Thonglor is the only one in the capital city with a Japanese-style hot bath. Following a stringent cleaning process, onsen powder from hot springs in Takayama in Japan are dispersed into the bath. Sink into these mineral-rich waters for a great pick-me-up before submitting your body to a relaxing warm oil massage or an indulgent four-hands Thai massage.