Children's Gym

I use my University gymnasium and locker rooms (including showers semi-private). However, they rent the pool (and thus the use of changing rooms) to a private swimming club in the region, giving lessons to children in the afternoon. Many children are accompanied by nanny. There is also a mixture of different cultures. Some women nannies and parents to provide all children in the locker room of women - including the boys who watch 5 or 6 years. The only policy they have is that children are not allowed in the gym and locker rooms ... which is obviously in conflict with the rental pool for swimming lessons for children. The staff raised the issue for parents / guardians, but with little impact because they cannot adequately monitor the changing rooms.
So what is the appropriate age for boys to stop being in the locker room for women? I'm OK with those layers, but what is the age limit cut? What is the acceptable level?

I'd say 5, but you do what you have to do. If you are uncomfortable complain to management.

Honestly, I'd be pretty wary of sending my 5 - or 6 years in a locker room that I could not enter with goodness-knows-who, when he had to get out of her swimsuit (which is a mini -combi, and zips on the back, not something very easy for a small child) on his own. At 5 or 6, children still may need monitoring while taking a shower, etc. And if I'm not someone who thinks pedophiles are not necessarily lurk everywhere, if my son will be spending 20 minutes trying to be stripped, showered, dressed and in a public place with adults around randomly, when I can not keep an eye on it all, I'd be worried. With a brother, of course. But otherwise, I would bring him in the locker room for women. If they are 5 or 6, they are not interested in distance in the bodies of women dressing, I assure you. Now, a 9 - or 10-year-old who is more capable and a little more attention to gender differences is another story, and I want them to be in their own dressing room.

Many gyms and public places like shopping now have the "family" locker rooms or toilets to solve this problem.

There is no specific age. Children must be accompanied by an adult in the bathrooms, locker rooms, etc. until they are old enough to take care of them. This is not just about getting molested, but it is a consideration. They must know how to dress and undress, what to do in an emergency, how to deal with an older child (or adult) to harass, etc.

layers and maybe a year or two layers if they have no toilets or family of his own.

and a mother of 2 boys, I take them as they are 5 or 6 and maybe even 7. If my husband can not come with us, then I must be the only one to undress and do things. Please keep in mind that these are young children, do you prefer going in a dressing room for men only? Anyone can be a pedophile and I hate myself if something happened to my children in a cloakroom. It's not like these kids are perverts or anything, they are there for a swimming lesson.

My boys are 9, 7 and 3 and my husband is not around a lot. I allow my older two to go in the men's room (depending on where we are) or in the locker room because they have each other. Waiting outside the door and listen to them. Sometimes, we use the bathroom "family" or I just take them in the ladies room with me.
In this case, I'd say about maybe 8 to 9 years old should be cut if he's fair and a nanny, but I would not feel comfortable sending my children into the locker room to change to a shower. Who kN.