It's three times the size of the Bangkok bathhouse. 

Bangkok’s first full-scale onsen is capitalizing on its surging popularity (seriously, don’t visit on Sunday afternoon) by opening a branch by the beach.

With its separate men’s and women’s zones, and zen-inspired decor, Yunomori Onsen & Spa Pattaya (Thepprasit Rd., between soi 9 and 11, 038-197-038, is a familiar sight for Bangkok fans—only it’s three times the size.

Other perks include a sauna in the female zone (which Bangkok sadly lacks) and an all-new “silk bath,” whose tiny bubbles create better buoyancy and are said to help relieve aches and pains.

All the water comes from Kanchanaburi’s reputed Wat Wangkanai Tayikaram hot springs. Unlimited onsen is B450 from 9am-midnight. Try a signature massage (B1,550), which combines Thai and Japanese techniques, or the 3.5-hour program that includes onsen, body scrub, aroma and herbal compress at B2,850.