Everything else! The roller coasters may be the most visable parts of the park but they are HARDLY all the park offers. In fact, my son is 9 and he counted IOA as his favorite park before he was tall enough to go on the big coasters! And you know, I promised him I would not get on them until he got tall enough. I was a moderator on is board BEFORE getting on the Hulk!
The park is eye candy! Go and enjoy!