You know, now when you mention it ...
There is only single narative reason to step inside that tomb ... and that is fact that those looters, or explorer, or graverobbers, or whatever you wish to call them ... are searching there for something valuable ... that, or general curiocity.
But we agreed on that being enough.
Now if you concider Swamp:
Either Ethel will invite you there, if you talk to her in Tiefling part of Groove ...
Or you meet her again arguing with those two peasants as you explore around Blighted Village ...
Or you went there to find out what is Kagha up to ...
Or you can appear there by pure coincidence, as you were exploring Underdark searching for the way to Moonrise tower ...
Or you can get there by even purer accident, when you try to sneak in Goblin camp around that casm, and rotten log will crack as you get over it.
If you take Risen Road:
Lae'zel is urging you to get there to find her kin ...
Or, you find out burning inn from Grove, if you use that Telescope ...
Or, im not quite sure about this one, but i would swear that nobody give you exactly best description about where to find Goblin camp, so i would dare to say that is quite possible to end up there while you are searching for it ...
Also, that road leads straight towards Baldur's Gate ... so if that is where you go, it would be quite logical for you to take this way ...
Sounds like we have enough opourtunities to me.
The only place on surface to explore that (i believe) was mentioned nowhere, is Tollhouse ...
The only reason i can think about, for coming there is either mission from Zhentarims (searching for missing cargo) and during that accidentaly discover this place aswell ... or being send there by Karlach, wich on the other hand is also in middle of nowhere, where nothing leads you, unless you are trying to explore everything, or you know where to look for her. :-/
One could teoreticaly argue that if you dont convince Aradin to stay inside the Grove, and meet with his group outside the Blighted Village ... they leave this way ... only to despawn in the woods few steppes ahead.
And maybe spider caves ... but since they are acessible only for explorers curious enough to either check well, or look inside houses ... i gues that is quite fine as it is ... as i said, not all locations need some quests to send us there, some can just exist for us to find out accidentaly.
The underdark is different story tho ...
While we have some quest here and there (except Kuo-Toa village, wich i quite often utterly forgot to visit) ... but i would dare to say that nothing sends us, basicaly anywhere (except mage tower, and that abandonned village where we fight Duergars) ...
Yes, we know we are looking for third fragment of staff / third clue about Grymforge ... but we dont really know where to look, and while ingame world is limited, Underdark is HUUUUUUUUUUUUUUUUUUUUUUUUUUUUGE and storywise should be concidered that way, i would dare to say.
We also know that we will need Sussur Bark for our best weapon in Early Acess ... but how are we supposed to know if this tree is what we are looking for?
I dont really think this is a problem for Underdark tho, since so many sidequests (and one main quest as the matter of fact) there is basicaly just "search for something for me" ... and during that searching we just accidentaly step on something else.
And i like it this way.
And then there is Grymforge ...
In this particular part of the game, its quite clear (as it is now) that Larian is counting on us being explorers, or completionist ... bcs if you concider just quests that are there, you explore half the map at best.
What leads you to that room where are remaining demons? Nothing as far as i know.
What leads you to that Duergar, who is trying to get trough cavein with his Deep Rothé? Nothing as far as i know.
As we are here, what leads you futher there, on that upper bridge full of traps where you find Shar statue and some Wizard robe? Nothing as far as i know.
How about that place where you meet Mimics? Nope. :-/
And that Lava lake with elemental, where you find amulet with soul of some Monk? Nah, nothing that i know about.
I must admit that wriging this down makes me a little worried, since it seems like futher in development we are, the less options there is. :-/
Feel free to tell me, if i forget some!
