Rumor has it, there is one.

Don't you need the attunement sphere from the crazy dude to get in this way ? Daedric quest Discerning the Transmundane is the one that brought me to Blackreach , I'd been playing Skyrim for 2 months already and had no idea such an awesome place existed .

No , that's Markarth . If you think that place is cool , wait until you see Blackreach .
You'll find it eventually if you finish the main quest .

Bethesda's dungeon design got so much better compared to Oblivion. Larger rooms, a lot of use of vertical space, more hand placed stuff, and most dungeons either have an alternative exit or a shortcut back to the beginning, so you don't have to backtrack through the whole dungeon to get out again.

And the use of exterior light: sometimes the amount of light in a cave is dependant on the time of day outside, and sometimes an area is completely open to the sky.

Thinks Markarth is cool.
Starts discerning le transmudane.
Enters Blackreach.
Sh*ts bricks.

Have to agree here. Was doing the max all levels exploit and decided instead of just running through like suggested (especially considering I was getting slaughtered for hours trying this way) to just dump the difficulty level (I always forget I can do that) and take my time cruising through there.. Was not expecting the dwarven ruins to be so huge, I also bagged a tonne of great loot, and loved the explorers journals and little story that went with it.

Then I finally walked in to blackreach and was very impressed at the place. Didn't realise it was so big until I'd walked around for an hour or so and decided to check the map and still couldn't see where the quest marker was pointing.. Then walked past the waterfalls... wow..

I kinda wish I didn't spoil the big lexicon puzzle thing by just reading what to do now as I'm sure it would've been pretty satisfying to figure that out myself.

And although it's beautiful and all I did find a lot of it very empty, like the War Room or whatever, pretty boring and empty.. Stopped going into the buildings after that.. Even the geode veins I think might be glitched as I just kept getting corundum ore, no soul gems.

Also I despise dark places, especially when there's enemies so I can't use candlelight to explore thoroughly. Wish mine could glitch and light up, looks awesome in that picture.

The Geode veins are essentially Corundum veins that use a different graphic and a weighted loot list, so the odds are skewed in favor of Corumdum ore. Had this happen on my first character through there and was rather annoyed, siince I already had a ton of the stuff in my smithing supplies container and wanted soul gems instead.

I did not encounter the Dragon on my first character, as I did not know the trigger yet, but I did on the second. If you're going to trigger it, be prepared; he's a Named boss-class critter, with all that entails, and will kill you if you try it at a low level.

Because this topic is about Blackreach I'll ask you one question here about it. Can you enter to Blackreach without main quest? I have visited there with my first character because of the mainquest but all other characters are unable to get there because they haven't found Attunement Sphere. Is it possible to find it with out getting the mainquest on certain point?

I still have the attunement sphere in my inventory, didn't do anything with it at all. Just enter through I think "Alfthand" (Something like that) dwarven ruins and you can make it all the way down through the Falmer lair into Blackreach.

EDIT: Also it does not matter about the main quest, you can go to Septimus' outpost at any time and quest for the elder scroll.

Cheers for the info about the geode veins and corundum stuff.

So now I'm interested, if I haven't even triggered any dragons yet, Have not been to whiterun or talked to the Jarl of Whiterun yet.. I assume I can't trigger the dragon down there since I don't have shouts? Any other way to do it??

The graphics don't hold a candle to Skyrim.