Younger children can have fun in Cast Away Island (180 ways to get wet) and he/she can go on a couple of rides with you.
9 months is a little too young for Canobie Lake Park.
Canobie lake has one of the largest amount of young kids rides of a classic amusement park challenging story land. That being said, ages 2+ (when they can walk and sit straight up on their own) is best. For under 1 year olds, the water splash area has very shallow water with supervision. Going on a family ride with them always works like the train, carousel or ferris wheel. Good luck!
Like all amusement parks, there really aren't too many rides for children under 3. They mostly need to at least be a toddler. There is a height minimum for all rides, some are posted no children under age 3. They need to be independantly stable.
There is a kiddie section with shows and stuff, not sure if he'll be able to get on any rides. If you have one of those carriers that you wear is probably the best, and wear spf 😁
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