The terrain here is rather uneven so building on here is tricky. The area does have several large buildings already and a fair amount of open water. The Lighthouse will take center-stage in this settlement and can be used as an extension of a rather large fortress if you so desire. There are plenty of options at your disposal and enough space to create a stunning settlement.
Murkwater Construction Site
Most of the building area is flooded leaving you with not a lot to work with. There is a reasonably sized building and a few other things you can expand to at least improve happiness in the settlement and get it running. The large amount of water however, is perfect for setting up water purification systems and growing crops etc.
This is one of the nicer places to be creative with a settlement. Why not try building a leisure resort? With plenty of dirt to plant crops and build almost anything you wish, as well as access to open water, there isn’t much stopping you from creating a perfect Commonwealth getaway.
A tiny little outpost with a small two-storey structure in place, there isn’t much you can do here in the way of building. There are some established crops and a couple of settlers here already so you do not need to do too much work to make it viable, at least for a small amount of settlers.
This settlement holds a radio tower and is initially occupied by Raiders, notably the unique enemy Boomer so be careful when approaching. The power grid is already up and running and there are some very basic structures in place. The buildable area is quite small but you can build vertically and it can be a nice self-contained fortress if you so choose.
Red Rocket Truck Stop
This will be the first settlement you will come across after leaving Sanctuary Hills as it is just outside of there. Not only does it come with a plethora of scrap, workshops and other handy objects, you can also acquire a friendly canine companion. It is an unestablished settlement but you can soon get it up and running with some basics. The garage here is also perfect for storing Power Armors you will collect on your adventures.
What was once your home before you entered Vault 111, things have changed a little in the intervening years. This will be your first settlement and it is a massive area, filled with plenty of structures to scrap or expand as well as areas to plant crops and create water supplies. This is one of the best places to make your base of operations because it is easily defended and easy to set up supply lines to and from the settlement. Even if you wish to expand your horizons to newer settlements, Sanctuary Hills is an excellent introduction to settlement building as you will visit it many times over the course of several quests so you can always check on your progress.
An interesting place, The Slog is populated entirely by Ghouls but once you gain access to the Workshop, the settlement welcomes any and all settlers. While there are already plenty of crops and a large structure here, careful planning is required because the buildable area can quickly fill up if you focus too much on turrets or too many fences. Try scrapping some workstations to free up some space and decide how you wish to proceed before building anything.