 The river valleys drain from south to north where they run into Port Hacking, the extensive but generally shallow harbor inlet which forms the northern border of the park.When looking across the park from east to west (or vice versa) the rugged folds of valley after valley fade into the distance.The geology of the site consists mostly of the Triassic Hawkesbury Sandstone with some sections of the park having the more recent richer Wianamatta shale capping.