Kiruna owes its existence to the world’s largest iron-ore deposit, 4km into the ground, and the action happens 914m below the surface. A visit to the depths of the mine consists of being bussed to a closed-off section of a mine tunnel, where you can hear mind-blowing stats and view truly giant mining equipment, such as the mills used to crush ore. Tours leave from the tourist office daily between June and August and with advance booking the rest of the year.