I've only ever been once as a visitor when I was 16 - it was a strange experience.
I was in boarding school back then and my best friend staged to CTB because they wanted a few free days from school (don't ask...)
Well, it worked. They thought their flimsy attempt of swallowing a handful of sleeping pills was a cry for help and the hospital stuff then forwarded my friend to the closed youth psych ward, where they wanted to keep an eye on them for at least a week.
I remember after 3 days I was allowed to visit, in the company of a teacher from school.
It was all so strange, similar to a prison what you see on TV shows. With bars in front of the windows and every hallway had locked doors that could only be opened by staff.
We were lead into the visitor room where there was only a table and 4 chairs, nothing else.
My friend was then brought to us and we wanted to hug but a member of staff immediately said "no physical contact!"
We were allowed to speak for 10min, then had to leave. I remember I cried on our way back, thinking I need a plan to rescue my friend if they don't let them leave after the week. Luckily they were allowed to go after the 7 days.