I was just reading Tales from The Yawning Portal for DnD 5e and while having a look at the map of the Hill Giant Stronghold from the adventure Against the Giants I saw that the room with the number 5, the Maids' Chamber is not accessible. There is no door that would lead to this room. It's completely surrounded by walls and there are no secret entrances. But there are multiple enemies in this room and the description shows that it's a normal room like every other one.
Is there an official way in the adventure that I overlooked that allows to access the Maids' Chamber? Or has there perhaps been an errata that I just wasn't able find on the net that would explain how to access this room?
My research has revealed nothing in this regard and I haven't seen anything in the book on the pages 165 to 172 which describe this level of the stronghold. I am looking for official explanations for accessing this room. I can always just place the door wherever I see fit if I can't find any official source. I'd be interested in information from other editions, too, as the adventure was originally written in 1981 for the original AD&D according to the information box on page 166.