The State Coal Mine is the best reason to visit Wonthaggi, and one of the most authentic industrial heritage sites in Australia. The mine operated from 1909 to 1968, extracting black coal from beneath the Bass Coast, and the heritage area preserves a substantial portion of the surface infrastructure — engine houses, boiler houses, workshops, the lamp room, the manager's office — in a state that gives a genuine sense of what the working mine felt like.
The underground tours are the highlight. Guides — many of them descendants of mining families — take small groups down into the old workings through original access tunnels, explaining the conditions, the tools, and the daily life of the men who worked below ground. The tours run on weekends and school holidays and are excellent for adults and older children. Above ground you can wander the heritage site independently for free, or join a surface tour. Allow two to three hours for a full visit.