Palmerston town is located on the summit of an ancient submerged volcano, a formation that’s also called an atoll. The atoll is composed of more than a dozen sandy coral islets which together form a ring along a coral reef and enclose a lagoon. For better or worse, the reef sits too high at the surface, therefore, no planes can land on it while helicopters don’t have the range to reach the place – making it only accessible by boat.