Creosote bush in bloom. Arizona-Sonora Desert Museum. We got there at 7:30 am for a bird walk with a docent (trained volunteer) and we stayed until about 5:30, when the security guard was locking the gate. Wow! This place is amazing! We've had several people tell us we have to see this... and they were right! This is a LIVING museum, much of it outdoors with all of the plants and animals of the Sonoran Desert. They showed us the invisible fencing that keeps the animals in a natural habitat without bars. They showed us how they use latex molds to create fake rocks (both for weight and to hide lighting and wiring). They've even built an artificial cave so you can explore underground passages (Yes, the area has lots of caves). They have an interpretive area explaining the rocks and minerals in the area. They have an aviary filled with all kinds of birds and another aviary filled with just hummingbirds. It seem that hummingbirds migrate through the area and pollinate the cactus when they bloom. They have large animals; mountain lions, bears, wolves, coyotes, ocelots, bobcats. They have small animals; reptiles and snakes, pack rats, kangaroo rats and a grasshopper mouse that is carnivorous and howls! They have interpretive displays about how termites and ants benefit the desert. They have prehistoric animals; sloths, dinosaurs, horses and other animals they've found fossils of in the area, showing that this dry desert was once a tropical environment. Wow! If you're ever in the Tucson area, you MUST see this!