Stripping down to your birthday suit and soaking in steamy natural hot springs is a quintessential South Korea experience. That’s especially true in Busan, home to the country’s two largest jjimjilbang (Korean spa complexes)—and when we say large, we actually mean enormous. Indeed, these aren’t just the biggest spas in South Korea, but probably in all of Asia.

Visiting and etiquette are fairly straightforward. On arrival, an attendant will provide a locker key, a cotton shirt, and pants. Change, shower, then start exploring and unwinding. Get naked—don’t be bashful, everybody does it—when using the actual gender-separate spas, and wear your “robe” in the labyrinthine communal areas, which include themed relaxation rooms, restaurants, and sometimes karaoke booths.

One likely wouldn’t guess that what claims to be the largest spa in Asia is located in a mall, but Shinsegae Centum City is not an everyday mall. It is, in fact, the world’s largest, a 16-floor small city that includes four floors of golf ranges, a basement food hall, a children’s theme park, and, of course, Spa Land. Here you’ll find more than 20 separate spas, scented steam rooms, saunas, snack bars and restaurants, and more. Visits are limited to four hours, and children under the age of 13 are not permitted.

Located at Hotel Nongshim, HurShimChung is Busan’s other spa heavyweight. Spread over five floors and 4,300 square meters, the spa offers facilities that include roughly 40 different themed baths, a fitness centre, a beauty salon, and a German-style beer hall. Children over one year old are allowed, but those with numerous tattoos are not.

Admission to both spas is a bargain, ranging from ₩8,000 to ₩13,000 (US$7.20 to $11.70); rates are slightly higher on weekends.