Vanilla， played with friends

Moat

Dig a circle of moat.
Then push up the inner circle horizontal line, build wall when we have enough resources.

Tame some 2 star wolves and put a bunch around your house you wont have to build anything the wolves will just kill what ever comes by except other wolves and drakes cuz are from the snow biome and they wont attack things from their own biome, even if they could drakes fly.

I try to avoid building right on the shore anymore. I came up with ways to put walls etc to mostly prevent them from going around but it was more work than worth the trouble.

That said, in my current play-through I found that building along a creek/ river with a close shore on the other side, caused the event swarms to approach from across the river. So far they have been easy to shoot and one troll event only had one troll show up. Lit him up with fire and he just walked away.

Dug a moat around the hillside and planted some trees to act as troll blockers on one side, but the actual shoreline along the dock and buildings has no "defense" at all. Before I put the trees up though I would get a troll in that one side pretty regularly. They seemed to spawn often on the hillside right where I put the base.

I had put stonewalls under the water around my base just high enough that you can hardly see it, but you can't swim over it.. Mods make(according to my experience) less damage in water to structures. At least two troll attacks in the water, on my stone walls have made as good as no dmg.

And for the rest, I just go out and fight the mobs. No (in my opinion) ugly moats or plateous necessary.

I built my main base on the sea shore. I do not try to make my base impregnable; in real life there is no such thing. My idea is the same as the real world, use fortifications to channel attackers. So I build walls (wooden or stone) completely around the land approaches to my base with a couple of gates. Walls can be extended a couple of meters into the shallows without raising the ground. I haven't put sny defenses along the shore. I do make sure the entire interior of my base is within the anti-spawning range of workbenches, some of which I built specifically for this property and to enable wall/gate repairs if needed.

In my experience, mobs from the Meadows, Black Forest, and Swamp biomes prefer wading or swimming around the seaward ends of walls to attacking walls or gates from land. I snipe them from the shore as they do so. Most of the time, the survivors are easily dealt with in melee combat.

Caveat 1: Drakes fly over walls. I planted two staggered rows of trees four meters outside the walls to reduce the area of the sky from which they can attack.

Caveat 2: I have been hunted by wolves but only a couple of kilometers outside my base. I don't know if they will swim around my base walls.

Caveat 3: Since raid pathing was changed in June, I've only been raided by drakes.

Caveat 4: If you plant crops,keep bees, or breed boar outside your walls in fenced enclosures, don't forget to put up a FREE LUNCH sign.

Ya found out the hard way undead can walk on the sea floor and shoot my boats, I just don't live to close the swamp anymore, I make a land down the way and make a road there

I use moats, and high walls on my side of it. At the ends near water I usually curl the moat out a bit away from the base both directions. Then put a stake walls gauntlet at the ends. You start learning how far out to go away from the base and the mobs tend to give up, or get enough out of aggro or sight range to care.

Only raid events I have to pay attention to. But even those have never got to the inside. Usually end up shooting a few, then the event ends with minimal damage.

I do the same as Trakehner. Where my moat meets the waters edge I put up an earthen wall. I take it out about 10 foundations then turn at a right angle away from my base and continue for about 10 foundations. This seems to work.

I never tested the distance needed so you might not need the walls to be so long.