During World War 1, did the trenches extend uninterrupted for the whole length of the front, or did they have ends? What happened to the trenches when they reached the alps or the English Channel?

by elephantofdoom
DuxBelisarius

These are pictures of the [Swiss border] (http://www.firstworldwar.com/photos/graphics/gws_gertrenchswiss_01.jpg) and the [Belgian coast] (http://farm9.staticflickr.com/8087/8481825367_48ed4f71ab_z.jpg), where the trenches of the Western Front did in fact come to an end. Of course it should be noted that the construction of the trenches varied based on the topography, terrain and water-table, as I note [here] (https://www.reddit.com/r/AskHistorians/comments/41adfu/wwi_trenches/).