This is the 2821st most frequent Japanese word.
館内
"館内" means "inside the building" or "inside the facility."
Here, '館内' refers to within the premises of the library, specifying the interior or bounds of the building.
図書館内では静かにしてください。
Please be quiet inside the library.
In this context, '館内' is used to indicate the interior of the museum, emphasizing the rules applicable within.
美術館内は写真撮影が禁止されています。
Photography is prohibited within the art museum.
This usage of '館内' implies the internal area of a general facility, hinting at navigational assistance or layout within.