Being in Carcassonne one should visit the Eagle Show - birds flying over your heads with Carcassonne's fortress as a landscape. Unforgettable!!!

About the crowds. I'm not sure that in May it'll be so crowdy.

By the way I'd not recommend anyone to spend his money and TIME! on a visit of Carcassonne castle. You just walk along the walls without any great views. For me going around the walls was much more appealing.

Alex Jerusalem Israel