About 7km south of Port Arthur is Remarkable Cave, a long tunnel eroded from the base of a collapsed gully, under a cliff and out to sea. The waves surge through the tunnel and fill the gully with sea spray (and sometimes water – watch out!). A boardwalk and 115 steps provide access to a metal viewing platform. Hardcore surfers often brave the cave, paddling out through the opening to surf the offshore reefs beyond.
From the car park, a walking track heads east to Crescent Bay (four hours return), a magical arc of white sand backed by some of Tasmania's most impressive dunes. Just before reaching the beach, a short sidetrack climbs to low Mt Brown, from which there are good views of Crescent Bay, Cape Pillar and Tasman Island.