These old siver-lead mines were opened in 1840s, they were only worked for a few years and the tunnels are still there. You can get to them from a walking track that leads off Sunnyside road. Its in a small reserve funnily enugh named Wheal Watkins reserve.
The Burnside council historical society run guided tours on the 3rd Sunday of each month at 1.45 $7 adults, $4 students. Bookings ring 8366 4200