Heron Island is an 8 hectare, 0.8 km long, densely forested sand cay on the leeward edge of a flourishing 27 km2 coral reef platform. Straddling the Tropic of Capricorn, it sits approximately 80 km from the mainland and is one of several islands that make up the Capricorn Bunker group.

The dominant vegetation is Pisonia grandis forest which, with the surrounding dunes, provides nesting habitat for thousands of migrant and resident birds, most notably the 100,000 White Capped Noddy Terns that nest here during the summer breeding season. Heron Island is also a major green turtle nesting site.

    

Heron Reef rises out of 40 metres of water and includes an extensive reef flat as well as a deeper lagoon dotted with patch reefs. The reef rim is generally exposed at low tide. Separated by a deep channel from the adjacent Wistari Reef, the Heron Island area possesses a variety of habitats and conditions appropriate for research and education purposes.