This is early Sep. 2024, the entrance fee is now 240 baht -- still cheap by many standards but no longer affordable for many working-class Thai gays, and with the Thai economy sputtering, this may explain why this place is seeing more Asian tourists than it used to. Out of the four guys I had fun with last night, one was from Vietnam, one from Jordan, one from Indonesia, and the last was Thai. I speak Thai pretty fluently -- judging by the conversations around me, I'd say the majority is still local Thais (plus lots of silent Thai guys too!). There are still very few Westerners, I think I counted three, plus the Arab guy. There are still a lot of young guys. The staff at reception are still friendly. The shower floors are still a bit slimy in places; there are still overflowing wastebaskets full of tissue paper, etc. Some things never change, but one of these things is that I have never been disappointed at 39. The place was jam-packed probably well before I got there (Sunday 6pm) and was still busy when I left around 9pm. To get a fresh towel, you have to ask the guy who hands out keys and towels on the first floor. There are two open-air "gardens", one for smokers, one for non-smokers. The top-most floor is almost like a tree-house: up a very steep ladder with tiny rungs, no furniture, guys sitting around the floor having fun. Take care on all the stairs: stoop to avoid low ceilings, hold the handrails, go slowly. It's easy to slip and fall. The guy I had the most fun with was a local Thai, 57 and fit, very friendly. There are plenty of gorgeous guys at this sauna, many average ones too, and of course some truly out of shape dudes, but I think the variety and diversity are a good sign, unlike at some cliquey other saunas. Also, 39 is easy to reach, just get off at BTS Saphan Kwai, take the exit on the West side of the street, walk south one block.

Old school sauna. Not modern but all facilities functional. Staff very friendly, no age or ethnicity discrimination. Cheap entrance fee 200 baht. Always plenty of hot guys, mixed ages. Busy after 5pm and weekends. Choose this one over more expensive saunas. You won’t be disappointed. Have been here many times and have never came away disappointed.

I go there often and I am never disappointed. Guests are mainly Asians of all ages, but on average quite young. As long as you smile and talk a little, relationships can become good qualities. It is also true that management does not distinguish between age and ethnicity. The staff are also friendly. From these bases, it is easy to give your whole body to make this evening a very good time.

I visited Underground Sauna on the eve of 11.01.2019 and had a very pleasant time. There is no discrimination on the base of race or age with one of the cheapest entrance fees in Bangkok. There were masses of good looking Thais and other Asians, hardly any Caucasians. This is probably my favorite sauna in Bangkok. My only criticism could be that they should make a better effort with cleanliness. However if one can ignore the piled up rubbish one can have a very good time.

I've been going there for years and it never disappoints. The crowd has obviously shifted toward Asian tourists a bit, but there are still plenty of Thai boys of all ages to be had. Staff and management are also very nice -- there's a family vibe at the place.

exciting sauna. Friendly staff. customers are mostly young thai guys handsome and in good shape. a few chinese and farangs. cheap admission: 180B . underground dark rooms WOW that's Heaven. highly recommended place especially on all naked days

I was there on Friday night, a naked night, the first day of Songkran festival. I was friendly greeted by the staff. It was packed with local Thais and I had so much fun there. I really recommend it if you are into local Thai guys.

A friend and I found this place on accident last Friday. It was naked night and probably about 50 guys there. Action everywhere and I really did not see anyone ugly, fat, or old. Definitely go again

Have been there many times. If you are into young Thai guys, you may be a bit disappointed. I went there on Sunday afternoon until 7 pm. Crowed, but most are guy in 40s and not in good shape. It used to have many young Thai guys go there on Sunday.

I've just come here tonight. All of them, just walk and walk and walk. I touch some guys but all refused, Im not hot but not ugly. What was going on there ? Boring.

Came on a weeknight. It was pretty busy. A bit more older guys than other saunas, but just as many younger Thais as well. Sauna facilities themselves were average for the area (so somewhat rundown).

I went to this place on last Friday. Didn't expect that much fun after went to two other places last week. I have to say as of now this place on Friday night is the most my recommended place to visit. The theme will be naked or gym night. Once you paid the entrance fee and enter the locker area they are right away you see everyone naked. Most of them are real Thai. Most of them are younger than 30 and good shape. You will see few foreigner. I met with one Indian mature and we had lots of fun. On the roof top area drink 9-10 pm is the mask period as of Friday theme night. The place is clean. They don't provide lube or condom. You must bring your own if you want to have hard action. If you like real Thai taste. I recommend this place!

The entrance fee is 180 bahts and you can get a locker. I saw one handsome guy when I enter but he going to leave that time. And then I go into the sauna and wait for next target, but after waited for 2 hours, I finally found one but he was grabbed by another muscular top. I left with regret.

I'm living in Bangkok (for 10 years) and going there for approx 2 years now. And in 90% of the times had a great time. But for the last 3-4 months I see audience shifting from 100% slim to almost 80% large (fat). No worries, these guys have the perfect rights to be there but they tend to be more "pushy". So the general atmosphere is changing, a pity.

Customer almost are Thai as in many review. Yesterday, I went there with theme UNDERWEAR. All guys, they are so sexy with their underwear. I got a lot fun...But you have to take condom and lube yourself. And its my first time here! Cool place! (Sorry for my English not good)

I had such a great time here. I'm a tourist and went to have some local fun, No disappoint at all! Guys are very friendly and open and very hot. Went on No Towel Night and the party was nonstop. Arrival staff greet you with a smile and the visit just gets better from there. Go, you won't regret it!

I had such a great time at this local place. Very friendly guys and multiple floors of fun. No towel night, very hot and filled with sexy guys.

I was there last Friday night but it was full of local guys. If you like the locals it's the place to go. Especially, Friday was a no towel night so the place was FULL. Unfortunately, my category, bear is not that popular there but still had some fun. As in the review below take your own condom with you !!

Happening place. Even the police visits. Because of this visit the distribution of condoms and lube HAD TO STOP I learned at my latest visit. Play safe and remember to Bring Your Own Condoms ! Then you will have a lot of fun there.

The sauna to meet hot Thai men. I came from Hong Kong with my family and had only little time, but I could still find some fun within the hour. 39 has the best sauna atmosphere in Asia (because most places are hot and smelly on some floors). The staff cleaned it very frequently. 這是一個曼谷必到的同志桑拿 與香港比較，它真係好大分別

OMG. Very fun there. Nude Masked Party on every Friday night 7-9pm is something best ever. Not come there on Friday night, not reach Bangkok, the capital of gay Asia!!!! Come earlier to make sure locker available for you!

Great local place. Dont spred the word or to many tourists will come. This is a local place, cheap entrance, everything is basic but good. (Large) beers have a fair price, darkroom is huge, ok steam sauna a bit small. And I may look dark and scruffy, the place is clean and the staff is friendly. I went there many times and yes some days you return home "unsatisfied" but in most cases its just a lot of fun. Every day between 5-8pm is good but Sundays are crazy fun. If you want to avoid the 75+ superfat foreigners that dominate Babylon then come here, you will find a fresh space.

When is naked nights?

Renovations taking place. Seems to have doubled the size on 4th and 5th floors. Dark orgy spaces but so dark it can be difficult to find your way out. Roof garden not finished yet.

这是一个当地人为主的桑拿，当然也有一些华人。喜欢这里的蒸汽浴室，总有疯狂的艳遇。音乐很嗨，有一次竟然还播放了中国歌曲。如果你下午没什么其他去处，来这里是一个不错的选择。

Is most exciting sauna in town, sexy sexy sexy, very close BTS and cheap admission.

The entry fee is modest but sauna itself really sucks...if you are traveler, just do not go.

Place is as sexy as ever. Though people spend a lot of time standing around. Perhaps more dark areas for people to get over there inhibitions would be good. The rooms are regularly cleaned with hot guys stationed on each floor to clean them. Came thurs 12/2/15 5- 8. Still about 20 guys when I left

Great sauna. I don't understand some complaints. It's clean, friendly, nice and hot sauna itself. Mostly locals. They won't jump on you like in Babylon but it's the challenge. I didn't have sex there after 5 visits but enjoyed the atmosphere and people around. Сауна идеальна для тех, кто любит в первую очередь хорошую парную. Она действительно классная. Много этажей, какие-то коридоры, темные комнаты есть, наверху курилка на открытой террасе. Есть бар, с дешевым пивом - Чанг 600 мл - 90 бат. В основном местная публика, которая не слишком кидается на фарангов, но при этом доброжелательная. Дешево (160 бат) и не сердито. Результаты зависят только от вас. Мани-бойзов нет, так что наслаждайтесь аутентичной атмосферой. Если есть желание найти что-то, проблем не будет!

Visited it on Tuesday night (10pm, naked). There are around 30 guys. I got an American guy.... Great night :)

Came here 13/9/14 Sat 8-10. I'm a clean freak and I'm saying this place is not disgustingly dirty. Rather it has just enough dirty action to be exciting (after all, we are not going to church). Unlike other glitzy saunas that I have been to that could use a few V pills, this place seems to have the right mix. True it's a little cramped and the gym and porn lounge seem more for show (if you can find them). I think this is a good thing. It doesn't distract you from the real reason you're there.

The most depressing sauna ever. Very congested, slippery, no air conditioning and above all, very dirty. I went on naked night, but the place was so much in sorry state I was not able to stay more than 30 minutes. Its a dungeon. The crowd is very local, but everything else is not worth mentioning

The best place for fun, great friendly people, great stuff and many Thai locals. Many young people and good music.

After visiting one of the newer immaculate saunas with not many visitors, I visited 39 Underground. It was AWESOME! I was there on naked night and it was wall to wall naked Thai guys. It didn't take long to get some action and had a great time. I will definitely be back when I return to Bangkok.

Очень комфортное расположение сауны Saphan Kwai BTS станция,(выход с платформы номер 3)идите назад (против движения)200 м, вторая улица справа от Вас, и Вы впереди увидите вывеску с названием сауны.Мне плохо понимающему карты я нашёл за 5 минут.Сауна состоит из 4 этажей всё довольно компактно и чисто. Персонал очень дружелюбный и всегда готов помочь.В сауне больше всего азиатов и местного населения что делает её более экзотичной чем европейская сауна Вавилон.При мне через 3 часа проводили дезинфекцию турецкой сауны а в это время на 3 этаже или на 4 (это такой lounge) можно продолжать искать приключения так как места для уединения есть везде.Пойду ли я ещё раз ДА это идеальное соотношение цены и качества.

The first idea I had when I walked in was "what dungeon I'm going in now?" And even it looks pretty run-down, it's clean. And the employees are very friendly. I was the only foreigner and it is definitely "a local" sauna! Customers are indeed very mixed. From 18-20y old skinny and muscled kids to 40-50 old skinny and muscled guys. It's a very relaxed atmosphere, the music is surprisingly good. It looks like everyone is waiting until the sun goes down, and they do. LOL Just be careful, take slippers and watch your head, the ceilings are pretty low! It's easy to find. Saphan Kwai BTS station, walk back (against traffic) for 200m, second street on your right and you will walk right into it. Entrance was 160 baht, so yes I'll go back again (I live in BKK).