What are the lines on a map that indicate the elevations of the land called?

The lines on a map that indicate the elevations of the land are referred to as contour lines. These lines connect points of equal elevation and are crucial for understanding the terrain's shape and slope. Contour lines provide valuable information, such as the steepness of slopes and the presence of hills or valleys, making them essential for various applications, including land use planning, civil engineering, and environmental studies.

Contour lines are typically represented with specific intervals, known as contour intervals, which help convey the changes in elevation over the mapped area. This allows users to visualize the topography of the land without needing a three-dimensional perspective. Understanding contour lines enables architects and planners to make informed decisions regarding site selection, grading, drainage, and overall design that respects the site's natural features.