The earth-sciences half of Science North, located on the west side of the city next to the Big Nickel. Visitors descend by elevator into a recreated working mine — guided by retired miners and millwrights — and emerge above ground through galleries on geology, meteorites, and the Sudbury Basin's billion-and-a-half-year-old impact crater.
The mine tour is the highlight. You walk through rough-rock drifts on actual mine equipment, with veterans explaining the trade in the dust-edged way that only people who did the job can. Allow two to three hours and bring a sweater — the underground stays around 10 °C all year.