Kangaroo Island is the third-largest island in Australia and one of the best places in the country for wildlife — largely because it has no foxes or rabbits, pests that wiped out native species everywhere else on the mainland. Koalas, kangaroos, wallabies, platypus, sea lions, and a large variety of birds are all present in numbers that feel extraordinary by mainland standards.
The island's main attractions are Remarkable Rocks (bizarre weathered granite boulders at the island's southwest tip), Flinders Chase National Park, and the Australian Sea Lion colony at Seal Bay. The ferry from Cape Jervis (itself 1.5 hours from Adelaide) takes 45 minutes to Penneshaw. Budget two days minimum — the island is bigger than most visitors expect, and the roads in the interior are unsealed.