Are they trans friendly? I’m a transgender woman, and I don’t use mens facilities. Also, I would prefer to not naked around anyone, Is that an option in the locker rooms/showers?

There is really no place for privacy at Spa Castle. The locker area where you will normally change is full of people changing at all times. The baths are 100% nude. Pools though are swim suited. There are restrooms where I think you can change in there if you prefer

I imagine they would be trans friendly, but I can't say for certain. I might consider calling them just to make sure. Showers are generally open and people will be able to see you. That said, they are generally segmented off into areas of ~6 showers per "area" (think of them as segmented areas in the larger spa area). While you are required to be naked in the area, there's a good chance that you can find a place to shower away from others. You'll likely be seen (though likely not paid attention to) on your way to them though. I hope this helps.