I have been to Tucson many times and every time I visit the Desert Museum. It is fabulous and a definite must-do activity when visiting Tucson. There is so much to see and learn at the museum, so plan on at least four hours or more. While there are water fountains throughout the outdoor museum, I would bring some bottled water too. The Raptor Flight is very popular, so if you plan on seeing it, which I highly recommend, plan on getting to the area at least 10 minutes before the demonstration show starts to get a good spot in the middle. Enjoy!