Just spent five days on LHI and 2 days in Sydney. No kids, had a great time. LHI is so beautiful and there is so much to do. We would have liked to have a couple more days because it rained on a few days. The walking tracks are quite rugged and on one there was ropes to help get up the steeper bits. They are all mostly very narrow and lots of rocks and roots across the path. The snorkelling was beautiful - lots of fish and coral and we even saw a sting ray. There was one spot where you could snorkel with turtles but we didn't get to go there.