Is it allowed to visit in Vatican Museum for a relogious jew?
ב"ה Shalom First, I should clarify that whatever applies to a religious Jew, applies to all Jews, but it's just that some are not aware enough what they are obligated. It is forbidden according to Halacha to visit in a church, since it is considered a place of idol worship. (שולחן ערוך יור"ד קנז,ג, ספר חסידים סי' תל"ה, חכמת אדם פד טו-טז, שו"ת אגרות משה חלק יו"ד ג' סימן קכט אות ו, שו"ת יחווה דעת חלק ד סי' מ"ה., ספר צידה לדרך עמ' 193) In addition, according to the Sefer Tzedah Laderech, (based on the above Chochmat Adam) it is also forbidden to visit the plaza where the people listen to the sermons of the pope because of the contents of the sermons make the place to be considered like a church. From my understanding, this does leave much other room in the Vatican other than official buildings and the library, which may be entered if they are not places of worship. All the best