A depression on a topographic map is a low area in the landscape, often represented by contour lines that form closed loops with the highest elevation on the outside. This design indicates that the land slopes downward as it approaches the center of the depression.
To understand this visually, imagine a bowl turned upside down. The rim of the bowl would represent a higher elevation, while the bottom of the bowl, where it slopes inward, represents the depression. On a topographic map, depressions are usually marked with hachures or short lines that extend inward from the contour lines, signifying the direction of the slope. These features can indicate areas such as sinkholes, craters, or simply lower ground compared to the surrounding terrain.