I took my kids when one DD was 5 and the little one was 10 mths.
DD5 (at the time)

d all things . . . but DD10mths(at the time) this is when she caught the DISNEY BUG . . . after our visit she was all about Mickey and Princesses . . . she'd point them out in stores, on TV!
Now, my two DDs are as addicted as me!
PS. Take him BEFORE he turns 3 so he can at least be "Free"!