What is the hardest dungeon in the game?

[Vexenu]

Factor in the requirement of using level-appropriate gear.

Some of the lower-mid level dungeons are absolute deathtraps, which is why no one uses them. Examples:

Splitpaw Lair
Dalnir
Runnyeye
Droga
Cazic Thule

I would argue that these are actually some of the most challenging dungeons in the game when adjusted for level and gear. I still remember a particularly amazing/disastrous group I once had in Runnyeye that culminated in a fight to the death with a huge train of goblins, in which four group members were slain and two barely survived. Probably the most intense and memorable battle I've had in EQ. And in Runnyeye, of all places.

Anyway, the question stands: what do you think is the hardest dungeon in the game when adjusting for level and gear?