Tucked away in a quiet nook between trees and ferns, under a canopy of ivy, the newly installed teak wood hot bath offers an onsen-esque experience in the spa's most idyllic corner. Heated to approximately 43C and filled with water infused with Epsom salts and magnesium, this addition to Old City Spa is our favourite of their heat contrast therapies.
Rotate between the hot water barrel and the yard’s ice bath that sits at a crisp 1C, or heat up in the Thai herbal steam room, regularly topped up with ginger, lime and lemongrass.
Most days, the space is filled with sauna-loving Muay Thai folk who head here for the Finnish and infrared sweat boxes, so our advice is to arrive early morning when they're all in training and you’ll have the place to yourself. Thankfully, visitors are capped at 20 people max, so whatever the crowd, serenity still rules.
65 Intrawarorot Road, Old City. B450 for two hours. Booking and details here. 10am-10pm.