Alma 49:4

But behold, how great was their disappointment; for behold, the Nephites had dug up a ridge of earth round about them, which was so high that the Lamanites could not cast their stones and their arrows at them, that they might take effect; neither could they come upon them, save it was by their place of entrance.

But they were very disappointed. The Nephites had dug up a ridge of earth all around them. It was so high that the Lamanites could not hit them with their stones and arrows. They could not attack them except through their entrance.

But they were in for a shock. The Nephites had raised massive earthen ridges all around the city—so high that the Lamanite arrows and stones couldn’t clear them. And there was no way in except through a single entrance.