Carman's Tunnel takes you into the mining side of Maldon rather than leaving it as scenery. The old tunnel sits in the Maldon Historic Area south of town, where restored forest and diggings show how much the gold rush reshaped the hills.
Check opening times before making it the centre of your day, as access can depend on volunteer or seasonal arrangements. Even when you only see the surrounding reserve, it helps explain why so many old workings still dot the bush around Maldon.