Very early on in the game I did some exploring along the western edge of the map, heading south. This lead me to finding the co-op and and a few other places. At one point I followed a pipeline down towards the lake where I was confronted by a raider guarding a big metal hatch in the ground. I quickly dispatched with him, then turning my attention to this doorway. When I attempted to open it, it blow up and of course killed me instantly, and I have yet to be able to find it again. I have scoured the area over and over but just cannot seem to locate it again.
Anyone else found this mysterious doorway? Its driving me bonkers that I can't locate it!!!

Could it be a random location. So it did not show up again yet?

Its possible its random but I doubt it, since it would probably have a load screen for another area or something. Its got me thoroughly confused regardless.

Looks like a cellar door? If so I gotten it to in a completely different location, its a random encounter, mine lead to a little bomb shelter with some loot, nothing major.

Well the good news is that wasn't a random world encounter. Well perhaps the raider and his dog being at their campsite or in the general area was the random encounter. But any kind of entry point to an interior cell can't be a random event because it's a physical and static object in the game world. Try checking that area carefully again from the top all the way to the bottom edge of the map. It's bound to show up.

This is why I always use the map marker when exploring unfamiliar terrain for the first time. It's always a good idea to use the map marker to spot your immediate location. Note any immediate landmark bldgs or other area icons on your map before doing an immediate save game. That way, you can always restart from your original position after kicking the bucket.

I was a little too impatient and didn't think anything about posting a marker or saving the game so I could start back there. Now I save every 1-5 minutes!

Also, I have extensively covered the area again and again and just cannot locate it. Hopefully I will be able to turn it up, or someone else can and share. If I do find it I will post a map pic, if there is anything good there.

I found one of those places up southwest of the vault near some high power towers. that one doesn't do anything for me. It says detonate, but when you try it the doors seem to open, but nothing else happens.

This is one reason I use quick save (F5) and quick load (F9) often. No loading screens and no menus.

Last night I came across the same thing, although for me it was near this random shack that's north of that crashed plane (it's northwest from Dark Hollow Pond and northeast from Bedford Station). I came across some guy (he wasn't named a Raider...I think he was named a scavenger) who found this cellar door lying flat on the ground. He was by himself and as I approached ( he hadn't seen me yet) he made some comment like "yes! It's taken me quite awhile to find this." He then saw me and told me to back off. I did as he requested--and I'm glad I did. I think he set up some explosives because 2 explosions occurred right in front of me where this cellar door was. It was really a cool sight. My 7 year old nephew, who was watching me play, ooohed and aaahhed at the sight. The scavenger then went into this cellar (bunker?).

I followed him inside and he attacked me. I shot him dead. There was some random loot in there, as well as a sleeping bag. There was also a cap stash (I think it gave me 95 caps).


Edit: contrary to what another guy said about locations with an interior cannot be a random location, I believe this IS a random location. Mainly because I found it in a different location than the original topic creator.

I DID save a few minutes after this event, so I will test and see if the location disappears after fast traveling or allowing some time to go by.