Planning a trip to Paris in late March and hoping to spend a day or two visiting the Loire Valley with its chateaus and wineries. I gather that we're supposed to use Tours as a home base. Two questions: any exceptional (doesn't have to be pricey - would probably be better if it weren't) places to eat around the chateaus or in towns? Also, how does one visit a winery? Dumb question maybe, but do we have to book a trip or is it a more casual, walk-in type experience? Thanks!