Mondo Knows Facts
Contour lines join points of equal height
Where the lines crowd together the ground is steep, and where they spread out it is gentle Each contour is drawn at a fixed vertical interval, commonly 10 or 20 metres on walking maps. Closed loops mark hills or hollows, and V shapes pointing uphill follow stream valleys. Reading the spacing lets you judge slope without ever seeing the land. It sits in Mondo's world geography collection, one of 200 facts that each trace back to the reference below.
Where this comes from
Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.
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More facts like this
The Mercator projection inflates the poles enormouslyOn this map Greenland looks as large as Africa, though Africa is about fourteen times biggerEvery flat map distorts area, shape or distanceA sphere cannot be flattened without stretching something, so mapmakers choose which error to acceptThe Peters projection trades shape for accurate areaIt keeps relative sizes honest but makes continents long and thin, and it is widely criticisedMap scale is a ratio, not a rulerA scale of 1 to 50,000 means one centimetre on paper covers half a kilometre on the groundThere are three different kinds of northTrue north, magnetic north and grid north point in different directions depending on where you standMercator's projection stretched the globe to help navigatorsThe 1569 map kept compass bearings straight at the cost of exaggerated poles
🗺️ World Geographyfact 190 of 200
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Tags: maps, cartography, terrain
Contour lines join points of equal height: the short answers
- Where does this come from, and can I check it?
- Where the lines crowd together the ground is steep, and where they spread out it is gentle. The figure is taken from USGS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
- Is this really a world geography fact?
- Yes. It sits on the World Geography shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
- What else can I read about it?
- The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.