23 striking photos of international borders from around the world

John Moore/Getty ImagesThe border fence between US and Mexico, near Nogales, ArizonaOn Wednesday, President Donald Trump will sign an executive order to begin the funding and construction of a border wall between the US and Mexico, one of his long-standing campaign promises. While its unlikely Mexico will pay for the wall, analysts at Bernstein have calculated the possible cost to be between $15 and $25 billion.

History, politics, and demographics have helped to shape the international borders that separate countries around the world.

Here, we've collected 23 photos of what borders between various countries across the world actually look like - from walls, to rivers, to barbed wire fences, to simple road markings.

Talia Avakian contributed reporting on a previous version of this article.