Walking north

 At the end of the paved path, I found a rest area with a roof. As you can see the valley here is not much wider than the river.

A few hundred meters past the narrowest place in the valley the land opened out into the large plain that extends at least 10 kilometers, all the way to the sea. This artificial embankment was a bit strange. As you can see they had cut through it when they made the road, but they had build a concrete wall instead of just making a slope. After thinking about this for a while, I suspect that this wall was part of the fortifications that protected the inner valley. This could have been the first line of defense for forces protecting the inner valley.