Contour lines are lines drawn on a map that connect points of equal elevation. They help us visualize the shape of the land, showing hills, valleys, and slopes. When contour lines are close together, it indicates a steep area, while lines that are farther apart suggest a gentler slope. These lines are essential for activities like hiking and planning construction, as they provide important information about the terrain. For example, a map of the Grand Canyon uses contour lines to illustrate its dramatic elevation changes, helping visitors understand the landscape they will explore.