Gladstone is an industrial port city on the central Queensland coast, about six hours north of Brisbane. It is not a tourist town — alumina refineries and coal terminals dominate the harbour — but it serves as the main departure point for Heron Island and the southern Great Barrier Reef.
Heron Island, about 80 kilometres offshore, is one of the best reef experiences in Australia: you can snorkel directly off the beach onto pristine coral. Ferries and helicopter transfers leave from Gladstone Marina. Lady Musgrave Island, a coral cay further south within an enclosed lagoon, is also accessible from here.
If you are driving north along the coast, Gladstone makes a practical overnight stop. The marina area has a few decent restaurants, and the views across the harbour at sunset are better than the town's industrial reputation would suggest.