Fallout 4 created by Bethesda Game Studios.
Images used for educational purposes only.

Crater House is located along the northeastern shoreline of the Commonwealth, just a little ways south of the town of Salem. Walk a long ways east of Sanctuary until you hit water, in other words, and then walk south a little ways. Crater House is, predictably, in a bit of a crater, on the edge of the water.

Crater House is owned by the Children of Atom, and their little community is sporting some vicious defences. There’s a Turret with a good view of the entire edge of the settlement, another with less of a view, several Mines on the outskirts (including a Nuka Mine - be extra careful of that SOB), and the Children of Atom themselves, who are toting some rather dangerous Gamma Guns. Expect a significant amount of Rad buildup. Several of them are also carrying Nuka Grenades, which will do massive damage if they hit you. Not a good setup. Here are some tips for carrying out a siege:
  • Regardless of how you proceed, you need Rad protection. Gamma Guns will inflict large amounts of Rad damage, sapping your maximum health, and the surrounding area is just plain radioactive. Wearing a Hazmat Suit under Power Armor will provide more or less total immunity to Rads while still keeping you protected from normal gunfire.
  • Because Gamma Guns basically flood the screen with green energy it can be difficult to see. This is one of the few battles where you may want to switch to third-person mode to fight. It’s a little bit easier.
  • By far the best way to get through Crater House is to be stealthy and snipe from afar, possibly at night. The Children of Atom have lots of health, but they also, pretty much to a man, don’t have helmets. You can blow their heads right off their bodies. 
  • Stealthing along with normal weapons and closer-range attacks can also work, but be careful of Nuka Grenades if they wind up spotting you. You’ll have to enter the settlement to do this, so move slowly, hide when you can, and use silenced weapons or melee attacks. You can shut down the Turrets and spotlights via a Novice terminal in one of the shacks, which can help keep you hidden.
  • If you plan on shooting at these bastards openly, start with the Turrets - quickly, if possible - then remain on the outskirts and let them come to you. Stay well back and in the trees, where you can potentially avoid their Gamma Gun blasts, and remain moving constantly. Don’t stay in one spot or you will get nuked. Power Armor and a companion are highly recommended if you decide to go this route.
You’ll find depressingly little of use in Crater House once you’ve cleared it out. There’s a trapped trunk in the shack furthest from the land, a locked safe beneath the stairs in the southern shack, and, on the second floor of the western-most shack, a copy of the Wasteland Survival Guide. Given how open this area is, you may be best served sneaking down to the table, grabbing the Guide, and then leaving. The rest of the stuff here ain’t worth the effort.

One final note: a little ways south of here is Kingsport Lighthouse. It, too, is a refuge for Children of Atom, though they're a bit easier to fight there since there are fewer of 'em. If you're already packing anti-Gamma gear, you might consider stopping in and saying hello.