Kauai is the oldest of the Hawaiian islands, and the local government is intent on keeping it as natural and as traditional as possible. Because of this, they have strict building regulations in place. To stop the island from being taken over by skyscrapers and big buildings that take over the natural world, their rule states that buildings can't be taller than a palm tree! However, two buildings do break this rule.
The Kauai Marriott Resort and the Princeville Resort both break this rule - however, they were built way before the rule was established. So, they're forgiven for being a little taller than the rest of the buildings.