K.M.
When my son was 18 months old we went to Florida and spent one of our vacation days in Orlando. We went to Sea World and it was great. It is a smaller park, so you won't be there the entire day trying to see everything. They have this great children's area with sandboxes and a splash park. Then of course, they get to see all the "fishies"! I was really glad that we did that instead of Disney. It was a nice time and I think at that age he enjoyed it a lot.