Great Barrier Reef

The outer reef is closer to Port Douglas than it is to Cairns, and the unrelenting surge of visitors has inevitably had a detrimental impact on its condition here in places. You will still see colourful corals and marine life, but it is patchy in parts.

Most day tours depart from Crystalbrook Marina. Tour prices usually include reef tax, snorkelling, transfers from your accommodation, lunch and refreshments. An introductory, controlled scuba dive, with no certification or experience necessary, costs around $300, and a three-day PADI Open Water course starts at $850; certified divers will pay around $330 for a full-day trip with three dives with all gear included.

Several operators visit the Low Isles, a small, idyllic group of islands surrounded by beautiful coral reef just 15km offshore; there's a good chance of spotting turtles here.