Ball's pyramid is the world's tallest seastack. It's the sole remaining habitat of a species of giant stick insect that was pronounced extinct 80 years ago. It's the rarest insect in the world, and possibly the rarest invertebrate. It's 23km off the southeast coast of Lord Howe Island, which lies approximately 600 km northeast of Sydney and southeast of Brisbane, Australia, at the same latitude as Port Macquarie. It forms part of the state of New South Wales.