We were lucky enough to have a Panhellenic wing within a dorm, which consisted of the 3 chapter rooms and a kitchen. AFAIK, all 3 held rituals in their respective rooms- but getting there was another story! We had a basement storage area accessible only by the Panhellenic wing, where we kept our archives. It also had a lounge where we "staged". On occassion we had a janitor pass us on the stairs going to/from the basement and we got the funniest looks!
Initiation & chapter meetings were always held in our chapter room (blinds closed!), but we did hold a couple of others elsewhere. We held the return-the-pledge-pin ceremony in the campus cafeteria, but in a beautiful private room called the Teakwood Room. The walls, ceiling, and furniture were all intricate hand-carved teak, it was just beautiful. We held our Fireside in a dorm lounge, down the hall from the Panhellenic Wing. And then we had a sleepover in the lounge
I know people popped their heads into the lounge on occasion (it was also the location of the dorm's piano, which was a hot comodity on a music campus), but usually that happened during the sleepover portion and not the ceremony.
Most people realize that a closed door means keep out.