Actually, when i started playing during 40d, given the vague warnings on the wiki, i was expecting something Balrog-like in the depths of the earth. I was tempted to spoil it to myself voluntarily, thinking i wouldn't have enjoyed the surprise ('A fortress ending danger just by mining in the wrong place, when i'm still learning the game? It could be fun for veterans, but no way, i have to be prepared!' I was
so wrong, but i couldn't know it), yet i suspected that, as a first time happening only once, i should have let myself be taken by surprise.
I was still unsure about looking it up, and i was still avoiding the forum for the same reason.. the ironic thing is that, while looking for what HFS stands for, i got spoiled by the image in the warning for spoilers in the wiki. 'Peculiar chamber, what is this? And that cyan metal vein all around would be adamantine?'. So much for secrecy.
I so regret it. I would have enjoyed discovering the !!Fun!! by myself, a lot. I know i have mostly to blame myself for misjudging the situation, but that image put the final nail in the coffin, so to speak.
Even worse in the current version, it doesn't help the new players that by looking up HFS on the wiki it redirects to the Hell page.
In the .31 version i got spoiled by the forum topic titles. It's always better to keep the secret than to speak about it freely, thinking that the others 'came too late', because such a revelation can't be unspoiled, and, by talking about it without regards for those who didn't discover it yet, we basically take away from them the right to be surprised. I think that putting (spoiler) in a non-revealing title is more than enough, if they click on it they have only to blame themselves.
I would have enjoyed discovering the magma sea by myself as well, i think my heart would have stopped for a second seeing all that magma
but i don't really blame anybody for that.
Another possible source of spoilers are dwarf preferences in their profile, but it's more likely to think those are just possible creatures from worldgen, or goblin/human civ masters escaped from a 'mythical underworld' not in the game (well, mythical until the player discovers about it), or from other biomes, or legends with the [DOES_NOT_EXIST] tag (even though that's really unlikely for a new player to know about that tag).. if that makes suspect about a Moria like situation, i see it more as foreshadowing than spoiling.