Our family of 5 is planning to each wear a fanny pack that has 2 water bottle holders, in addition to the storage space.
I keep reading about checking bags before entering sites, and I'm wondering whether we will constantly have to part with our fanny packs.
Every museum seems to have a different rule, thus any universal answer given here is going to be wrong at one or more museums. The only perfect answer is to check each website or find out the day you show up. The Uffizi was bombed by terrorists in the 1990s and ever since then, the European museums, esp. in Italy, have been picky about what they let into their museums. You'll be glad they are careful.
About the only one I could say is a "given" would be the Borghese Gallery in Rome, where you have to check nearly everything--coats might be the only exception. Otherwise, it completely depends on where you are. I carried a large purse everywhere except the Borghese and Uffizi, and I think I would have been allowed to keep it at the latter, but we decided to check the bag for comfort's sake. I tried to check it at the Capitoline Museum and they told me to keep it!
Fanny packs will probably be OK at museums that allow large purses, but it is just going to vary. The good news is that the baggage checks I saw were all simple, secured, and free.
