Skiing may be a winter sport, but people in Copenhagen, Denmark, can race down this snowless slope year-round. The human-made mountain, called Copenhill, is covered in soil and grass. It also has a layer of plastic bristles coated in an oily substance. That lets skiers glide over the slope as if it were covered in snow.

Visitors to the artificial mountain can also hike along trails lined with more than 200 trees or scale a dizzying 24-story climbing wall.