I'm really not big on reservations but I'm perfectly good with getting up early and getting in line well before opening. How will that work out with seeing Pech Merle in mid June? Their site suggests reserving at least a day ahead. I can handle that, I'm just loathe to set an itinerary in concrete weeks or months ahead of time. I prefer to leave room to adjust as I see fit during the trip, which means I'm not exactly sure which day I'll try to see the cave.