Imperial City Prison
From the OblivioWiki – your guide to everything Oblivion
The Imperial City Prison is northeast of the Imperial City Market District and connected underground via the Imperial Prison Sewer, where you start The Elder Scrolls IV: Oblivion.
Prisoners include J'Baana, master trainer of Security, and Valen Dreth, the caustic criminal from the beginning of the game. Claudius Arcadia, the contracter for the dark brotherhood initiation quest A Knife in the Dark is also in one of the cells. Even if Valen Dreth still lives Arcadia is the only prisoner you can see.
