Editing Border (section)

=== Natural borders ===
[[File:City Lights at Night along the France-Italy Border.JPG|thumb|A photograph of the France–Italy border at night. The southwestern end of the [[Alps]] separates the two countries.]]

{{Main|Natural border}}
Natural borders are geographical features that present natural obstacles to communication and transport. Existing political borders are often a formalization of such historical, natural obstacles.

Some geographical features that often constitute natural borders are:
* [[Ocean]]s: oceans create very costly natural borders. [[List of transcontinental countries|Very few countries]] span more than one [[continent]]. Only very large and resource-rich states are able to sustain the costs of governance across oceans for longer periods of time.
* [[River]]s: Some political borders have been formalized along natural borders formed by rivers. If a precise line is desired, it is often drawn along the [[thalweg]], the deepest line along the river.
* [[Lake]]s: larger lakes create natural borders.
* [[Forest]]s: denser jungles or forests can create strong natural borders.
* [[Mountain range]]s: Many nations have their political borders defined along mountain ranges, often along a [[drainage divide]].

Throughout history, technological advances have reduced the costs of transport and communication across the natural borders. That has reduced the significance of natural borders over time. As a result, political borders that have been formalized more recently, such as those in Africa or Americas, typically conform less to natural borders{{Citation needed|date=January 2023}} than very old borders, such as those in Europe or Asia, do.