Originally posted by Maelstrom:

The main purpose of walls is to break mob line-of-sight (LOS). Mobs won't aggro if they can't see you or any base structures, they'll just wander around alerted outside.

Oh, that's VERY useful information that I wasn't (at least entirely) aware of. It helps to explain why at my main base, it's so peaceful. The only thing that has ever been attacked is a wagon sometimes when I leave it outside of the wall after gathering wood.

Meanwhile, at some of my smaller outposts, I've had issues with stuff getting destroyed....I haven't been building any kind of walls for those.

You have taught me things, so thanks!