Not all attacks on Sanctuary Hills comes from the bridge, and myself and others have seen npc's spawn right in front of them in the middle of the settlement.

Some people don't really like settlements all that much and would like to be more minimalist when dealing with them. On this playthrough (i'm lvl 15) I decided not to go crazy with Sanctuary. I only have recruitment beacons at Sanctuary and Red Rocket and taking a slower approach to building settlements.

Currently at Sanctuary I have 13 settlers, 16 food & water, 33 defense (3 turrets on carport roofs & 3 guards)
I do keep my settlers outfitted well with decent weapons tho

I was able to get a short clips of a small group of ghouls attacking Sanctuary and you can see how well a minimal and scattered defense works

This video also showcases some of the clumsy behavior of ghouls

https://www.youtube.com/watch?v=j9YCJzzppLc

Walling is a waste of time and I honestly do not understand why people like walls.

I prefer http://www.nexusmods.com/fallout4/mods/5787.

Walling can actualy work rly good in many settlments if you know where the attack points are.

I wall everything. The purpose of role playing is to treat the game like a story; stories imitate real life.

In real life, if I established a settlement in a town rife with Super Mutants and Raiders, I would make that settlement air tight. Besides, there's something comforting and exciting about approaching your settlement styled with walls, turrets and a skyscraqer made of junk walls and prefabs.

Wally World is a great place.

i actually walled in the Red Rocket, still not sure if i should regret that yet, and i was thinking of walling in Abernathy, just because of how the buildings are

but also this is to show people you dont have to spend a lot of time in settlements if you dont want, i just have 16 sleeping bags in the workshop house with a bar in the garage ara
i use the house with the terminal for my own and moved all the crafting stations over there, as u can see from video i only have walls on 2 sides of the growing area which is still in default location

I line the roofs with Turrets. Anything stupid enough to attack Sanctuary is converted to hamburger before they even reach the roads. I don't think a Raid has lasted long enough for me to participate since my last upgrade.

On my second playthrough I have a similar approach. I have a main two-storey building with 16 beds, a leisure area, and a shopping area, on top of which are tourets and lasers and the beacon. It gives a nice 360-degree defense. I also have a few tourets scattered around the settlement, near the bridge, near my crops, near purifiers, etc., but no walls. Seems to be working well. What I also do to ensure my guards patrol the perimeter is I put posts at a few strategic points.

Works well enough.

EDIT: Love that the siren goes off after the battle.

I think you can wall Abernathy but not too wide, it that makes sense. I've only witnessed one attack there but they spawned from the sides of the perimeter.

I've never seen an attack spawn inside the Castle, so I'll wall it up. It's just nicer anyway.

Walls work fine if you just wall off a few buildings in Sanctuary. I usually wall off the players original home, the home across the street with the work bench/garden and the lot to the left of that after building a 2 story attaching bunk house. I then leave one entrance into the area that is heavily defended. Works pretty well. Regardless of where they spawn in Sanctuary they always go for the heavily defended entrance and get destroyed rather quickly.

Although some of my settlements may have heavy lasers, this is basically how I defend all my settlements: https://www.youtube.com/watch?v=cgrsqD7cvvY

the sirens are really meant for when the battle starts, on a previous playthrough i had big wall and i liked to put a big 'kill zone' leading into the gate with wire fences zig zagging surround by turrets and guard posts. When that one was attacked, one of the guards hit the siren, which brought all the settlers to the entrance while the enemies were getting chopped up in the kill zone

so in theory you could look at the siren as a location alarm, u could probably scatter them at strategic points so if a settler is near there they can alert the rest of the settlement where the threat is

The only thing i have found walls to be "useful" for is protecting things like Generators, crops, water purifiers and other stuff that can be destroyed around the settlement. That being said, i do love walling off my settlements and building gates/defenses around it for the rpg aspect. To each there own, and that's the beauty of this game.

I think too many people have been listening to survivalist Rick Grimes...

"build a big strong perimeter wall and nothing can get at you"

Never works the way its supposed to half the time due to infiltration techniques, a smart tactician will know that you should only invest everything in your defense WHEN you know all the weak points of your stronghold, which can only happen AFTER being attacked a few times and not before.

With good deployment of turrets fully walling in a settlement is unnecessary. Walls are very useful in funneling enemies into your turrets and traps where they can be quickly killed.

It's mostly learning exactly where the enemies spawn on attacks and setting up your kill zones to wipe all but a few melee enemies out at a safe distance.

Be mindful about 'size' for your settlement. If you plan to really build in Sanctuary and build a lot of houses and power stations, then I wouldn't wall in your compound. Walls, flooring, fences; take a lot of space - on console any way.

I don't bother with walls. Which is a shame because it would be really nice to actually build some kind of fortress type thing. And see how that pans out against attacks.

I started out with walls and went over to a more open combination of some walls plus "turret stations" here and there.

If you build too many walls they start to make an impact towards your max settlement size limit, which is bad, because it's already pretty low to begin with.

My Red Rock is a fort. It's rather well protected, after all my Power Armor collection is there. My "Fortress of Solitude". It's funny to watch the big lasers finally get into the act and end the show real fast.

As I have to show up to even have the turrets go off, I don't build forts for my settlers. I arm them very well, and leave Power Armor with a core, at an increasing number of places. I have little trouble once I get there and they are quite effective with Combat Rifles and Shotguns.

That's not a official mod though. Matter of fact, there are no "official mods". I personally don't care one way or another, I actually use 1 mod. The one that changes the power armor sound into something much more....more. But some people on here have a hissy fit over stuff like this.

Wall. Every settlement I have has some sort of wall. It's silly that wooden walls are just as strong as concrete shack floors (as walls). But the walls help when I help defend. It's lame that when I don't help the enemies still get inside somehow even with 2 floors of walls and defense over 100. But walls are worth it to build. Supermutants in Survival are no joke. I didn't build walls until a legendary deathclaw killed all my settlers at Red Rocket. I was on my 3rd floor balcony when I arrived and saw the deathclaw trying to get to me. Walls help keep settler alive and keep purified water stocked at all times.

There are several things to consider before deciding to wall off a settlement:

1. Each settlement has very specific spawn points for enemies.

Walls can be extremely effect if you make sure they are between your settlement and the spawn points. Sanctuary Hills has a spawn point in front of the bridge out of town, and one behind one of the houses. Since Sanctuary is so big, it is easy to accidentally include enemy spawn points inside your walls.

The Slog has two enemy spawn points - one at the crossroads just outside of settlement, and one on the hill behind the swimming pool / tarberry pit.

Knowing where the specific spawn points are before you build your walls will save you time and grief. I personally recommend letting your settlement get attacked twice before building walls, just to pinpoint where enemies will come from during attacks. In my experience, this will stay the same for that particular settlement.

2. Build Size versus Benefit

If you are playing on console or a weaker PC, Build Size is a concern, and you have to decide whether or not it is worth it to have walls around your settlement or more buildings and decorations.

If you know the spawn points, you can always just plop down some turrets near each spot, and as long as you are in-town, any attacks will be gunned down before they get their act together.

3. Realism

I like to build walls around my settlements because it just FEELS right. Like someone else said, if you lived in an area with Super Mutants, Radscorpions, Vicious Mongrels, Mirelurks, Deathclaws, etc. I'd sure want to live in a walled community.

I also use the walls to create choke-points. I always put my gates close to the enemy spawn points, and then realistically man the gates with defensive structures, guards, and turrets.

It depends. Walls can be effective if you do it properly. If you want to just build a wall around the perimeter of the build area, it probably isn't going to do much to prevent attacks. If you build walls in stages though, with an outer perimeter wall, and more walls between the houses and closing off the inner part of Sanctuary, then they can help.

I don't wall my settlements. Once upon a time I did, but that ate up resources (turns out wood is actually a bit of a commodity,) build space, and time, especially since I had to plant my fences on a carpet just to get them to "connect" without an absurd gap. Sure, there's a mod to fix that problem too, but I'm waiting for real mods, not what are essentially code edits.

So instead I just plant a turret on virtually every corner of every house. Even if the bad guys do end up within the shanty town limits, they're mince meat between a bunch of settlers and all those turrets. The only real danger is a super mutant suicider. Walls do make shanty towns look nicer and more grounded in the world of Fallout's reality, but they're a tertiary concern. The LAST thing on my bucket list of settlement construction... after I've built every other settlement.

More than half the game is settlement planning and building. if you haven't built a multi tiered mega fortress with automated heavy laser, missile, shotgun and spotlight emplacements you've missed out on most of what this game has to offer. Plus the technical details in order to "wire" up those items takes some serious thought. I learned enough about switching power terminals that I tackled a light project here at the house, gotta say, probably not up to code, but the light works!

This is what I do. The natural instinct is to set turrets around the perimeter of the settlement. However, given the fact that attackers sometimes spawn within the settlement confines, it's best to set up perimeter defenses and interior defenses. I have three main buildings there. One is a bar on the first floor with a bunk house on the second floor. Another is basically my shopping mall with all of my vendor stands. This is a 2 story building with the floor for the second story removed, so it has a loftier feel inside. The third is my personal workshop and living quarters, which is also a 2 story building. The roofs of all three buildings are lined with heavy laser turrets and missile turrets. I have 2 heavy laser turrets on the bridge, and numerous heavy machinegun turrets posted around the rest of the perimeter and in various locations in the interior of the settlement. I've only had a few attacks at Sanctuary after over 260 hours of play time, but on each of these occasions my defenses have simply mowed them down almost instantly. I have all of my defenses connected through a terminal with spotlights all over the place, so they know where to point. My Sanctuary is pretty much impenetrable.

edit - It's also worth mentioning that I don't have any kind of walls set up at Sanctuary. I prefer having a view.