I took my 20 month old and 4 yo to Legoland this month. They both had a lot of fun. For a 2 yo, I'd bring a stroller and let him nap, ideally while we eat lunch. I'd pick Legoland over the zoo, because of the water park (just splash areas for small kids) and being physical. At the zoo, it's hard to see all the animals in some of the exhibits so he's on my shoulders or in the stroller, not running around. We really liked the aquarium at Legoland, though small and no strollers allowed.
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