Three day adventure tour on Fraser Island, the world's largest sand island. Only accessible by 4x4, using the beach as a highway. Went up a steep volcanic hill on the coast and saw dozens of tiger sharks and a few sting rays in the sea! Couldn't go swimming in the sea anywhere on the island because its so shark infested. Instead we swimming in crystal-clear freshwater rivers and lakes. Went walking through the rainforests and up huge sand dunes. Also saw a few dingos (wild dogs) on the beach.