Played fallout 3 and loved it, it's been a long time since I've been in the fallout universe so things are a bit fuzzy to me.

I have a question about locations. As I'm exploring I'm finding a ton of locations. My question is is there a quest connected to most locations? I just don't want to go and clear out the place and later find that im there and there is nothing to do.

From a strictly map-marker locations point of view, I would say more are NOT quest active locations.

The fallout Wikis list just about everything and anything that can happen there, but that can be tough to browse without coming across a ton of spoilers.

Size does give a clue, as most single room shacks and such are not quest locations, but maybe not always.

It's a very general question that is tough to really answer without tripping a spoiler boobytrap.