Maxwell Onsen was built as a proper Japanese-style bathhouse in the middle of Silom — three mineral pools, pine sauna, bergamot steam room,
Himalayan salt chamber, and a rest lounge for the space between rounds.
The bath hall is the centrepiece: a Kusatsu-style hot pool at 41°C, a warm pool at 38°C, and a cold plunge at 19°C, poured with mineral water sourced from Japan. A projection above the pools plays quiet Japanese mountain footage while you soak.
Every entry is ฿600 flat and includes a full Japanese meal in the tatami-floor restaurant — refills allowed — plus towels, locker, and use of the private nap rooms. Rest area lounges are set up for a full-day visit. Reception in the front lobby, bath areas one floor below.
Walk-in, men only. No age restriction. ฿600 walk-in — includes full Japanese meal, towels, locker.