I personally believe that the Monterey Bay Aquarium is the best out there. Every time we visit Monterey it is a must-see for us. It gets crowded because it is so popular, so try to get there as close to opening as possible. It is expensive to get in (and the food inside is pricey) but it is definately worth the price. They are constantly upgrading and adding new exhibits; the tanks they have are amazing (both the size of the tanks and the animals inside them). Don't miss it if you are in the area!
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