If you go to providence, stop in the omni plaza hotel (which is attached to the providence place mall). You can get a day pass for their amenities (pool, hottub, exercise room) for $15 per person for the entire day. So if the weather goes to shit, you can have access to all that plus the imax theater, Dave and busters and good restaurants all without having to go outside. It's also a good launching point seeing how it's pretty much right in the middle of the city.