I really enjoyed this one near Linz: eurothermen.at/bad-schallerbach/ It is huge, sauna welt bit smaller, but nice outside naked pool included.

I went to that place last year. It was really bad, at least in my opinion. Not even terms of sights, but the whole place lacked atmosphere and the personnel were not friendly. One of the worst spas I have ever visited.

There is a nude area, but also a large clothed area, and the majority of younger people stayed in the clothed area. Nude area was relatively small, and the vibe was not good, most saunas were empty. There were some naked women, but most people there were older guys. I would say the gender-ratio was 70-30 for men. Many older men were fully shaved and had impressive sausages, but I'm not that much into seeing them.

Maybe it would have been better on a different day. It was quite warm and sunny outside, so maybe that didn't really inspire locals to go to a sauna.

Assuming you'd like to see naked women in their 20's and 30's, definitely go on a weekend or after work hours on a weekday.

thermen Elysium in the Netherlands....
 

for 20/30, you should go to Thermen Elysium in the Netherlands....

I spent a Sunday afternoon and evening in the Stadtbad Neukölln. A good turnout. The swimming pool became flak after 16:00 I think. I would definitely return.

Vabali Spa is good--a pretty typical nice place, with some tourists since it's easy to get to and in Berlin.

Liquidrom is an interesting alternative. It has a pool with (relaxing, not particularly interesting) music, which requires bathing suits, and the rest of the place is a pretty typical German spa. What is interesting about that is that people are constantly dressing and undressing from their bathing suits, basically in the hallway. Quite a few tourists who are not comfortable with nudity (which has its plusses and minuses).

Recent reviews of that place look particularly bad, like the place has gone downhill. Have you been there recently by any chance?

Does this result in a lot of enf? I'm always most interested in spas that lend themselves to these situations, often with lots of tourists as opposed to those where everyone is used to and comfortable with their nudity. Do some keep bikinis on, and do staff enforce them to remove them if they do?

can you remember what time of day you went?

i'll be close y next month and want to avoid your experience

It was on a weekday, something like 2 PM. And it was in May. The weather was really good, so I'm sure it will be better when the weather is worse. Or I'd like to believe so. I have been there only once, so can't be really sure about anything.