2 of the most well known are The Great Barrier Reef and the Daintree Rainforest. Both of which should not be missed on a visit to this tropical region. Even if you don't want to get wet you should take a cruise to the Outer Barrier Reef. The colours and range of coral and fish are sensational. You can see all of this on a semi-submersible or underwater viewing platform for those who are not into snorkelling or diving.
Diving is available to anyone with reasonable fitness.
It is important to note that the Box Jellyfish inhabit the waters around the coast, mainly during the months of October - May, so swimming off the beaches that don't have nets is not safe. As the Jellyfish breed in the estuaries they only travel as far as the coast and swimming off the islands or on the Great Barrier Reef is perfectly safe year round. The region is split up into various townships along the coast. Most of the action happens in and around Cairns. This is where all the day tours operate from and the vast majority of accommodation is found.