I forget , it's a large chamber with high level Draugrs that pop out of coffins along the side of the room and the boss at the far end?
I did that early in the game and was really tough (one-shot killed most of the time), but the reward was worth it. I still have not found a better amulet and will never be able to make one with 3 enchantments.
I killed the Draugrs while still in their coffins using flame runes fired on the coffins, before raising the boss, but it was still hell. I had to leave Lydia waiting outside the room as she would always get killed in there.
But I didn’t think it was the coolest boss. I haven't actually met any cool or well scripted bosses in Skyrim, compared to other games. As fighting games go, I'm a big fan of Devil May Cry 4, there was some super cool bosses there, each one of them makes Alduin look kind of Nintendo.
Most bosses in Skyrim can be rushed against a wall while bashing with a shield and hacking with a sword/mace. Often you can exploit the game's pathetic pathing system for NPCs (they can't even jump), and pathetic combat in general, and stand at point where they cannot hit you while you can, or get them to get stuck behind an obstacle or in a corner.
Once you have the Impact perk you can spam many of them with fire and stagger them, and then it's all over for them. I actually use a mod that reduces the chances of stagger to make the fights a bit more challenging.