Heron Island has been the focal point for research on the southern Great Barrier Reef Province for the last 80 years. Heron Reef is an excellent example of a lagoonal platform reef with a sand cay developed on its leeward end, displaying typical reef morphological, sedimentological and ecological zonations allowing comparison of their windward and leeward development. Limited subsurface data indicate that the total reef section is only 150 m thick, consisting of stacked limestone packages, with a gently eastward sloping solution disconformity delineating the base of c. 15 m of Holocene reef growth. Holocene reef growth does not appear to fit the classical model, with evidence of much progradation on the windward margin relative to the associated leeward margin. Large dredged blocks of reefal material provide new data on the abundance of in situ framework in much of the reef and the importance of microbialite in the unification process.