Antichamber behind Vokun's Tomb

[Captain Crunch]

How do I get back there? I've searched all around Vokun's tomb. I already killed him/it.

[cfs111]

Stairs to the left and right of his coffin.

[Captain Crunch]

I know that. The gates are closed. No way to open them.

[Archnecrotyr]

This is the only listed solution.
"Vokun's Throne Room may be accessed by utilizing a follower to open the gate blocking the player from the antechamber exit above the first room. This is accomplished by bringing a follower after clearing out the entire dungeon (unconfirmed if clearing out the dungeon is necessary), climbing up the pile of rubble, in the first room, beside Anska, and using Whirlwind Sprint to access the walkway leading to the exit from the antechamber. The follower will run through the dungeon and eventually, in approximately 1-3 minutes, appear on the other side of the gate from the player. The follower can then be instructed to pull the chain, thereby opening the gate and permitting the player into Vokun's Throne Room."

If that is to much of a process for you, then just use the console to tcl and go through the gate and open it...