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A closed line joining points of equal height, showing the shape of the land.
Also known as: Isoline, Height line, Wiggly brown lines
Contour lines join points of equal height. Their spacing is the information — lines close together mean steep ground, and reading that spacing is the whole skill of seeing terrain in a flat map.
Joins points of equal elevation, so every point on one line is at the same height above the datum.
Contexts: Navigation, Maps
Conveys steepness by spacing: closely spaced lines mean the ground rises quickly, widely spaced lines that it is nearly flat.
Contexts: Navigation, Maps
Cannot cross another contour, because a single point cannot be at two heights — which is why an overhang cannot be drawn in contours at all.
Contexts: Navigation, Maps
Is drawn at a fixed vertical interval stated in the legend, so counting lines gives a height difference directly.
United Kingdom · Contexts: Navigation, Maps
A thin closed curve, usually brown, following an irregular path across the map and nesting inside or outside neighbouring curves without ever touching them.
Both join points of equal value; only the quantity differs.