There is a very old and traditional sulphur baths in the old town of Tbilisi, Georgia called Abanotubani.
I assumed it would've been originally a Turkish hamam and have only segregated sex bathing.
But doing some asking around with locals and Googling I now get the impression that mixed bathing is allowed at all, at least in some of the baths.
But what I can't find is the solid facts. I know there are a series of numbered baths. I know at least some of them some of the time are public and I believe men must be naked. I do not know for sure if there are also possibilities to rent a private bath for a group or for a group to visit a mixed public bath. Also if mixed bathing might be permitted only on certain days or at certain times, or if mixed bathing must not be naked.
Where can I find all the rules and information on how to use the Abanotubani baths? Or can we take a mixed group of about ten people to rent a private bath to use naked?