The Secret Sewer is a lair is added by Castle Volkihar Redux. It is designed to be a safe haven for the Dragonborn when starting out as a fledgeling vampire and may not yet have been able to gain access to the castle when finally finishing the entire Dawnguard questline.
This lair is not available as a home until the quest The Scent of Old Death is completed.
This secret lair is located inside the city of Solitude. The sewer entrance is actually a manhole cover found just outside the rear of the Erikur's House. There is a shadowmark "protected" on a barrel just outside the back door.
Once the associated quest The Scent of Old Death has been completed three more manhole covers will become available for entry using the key gained from the quest.
This is by far the most comprehensive external world starter vampire lair provided by Caslte Volkihar Redux. It has four usable coffins, an alchemy lab, Blood Bucket, Vampire Cattle to feed on and storage.
Initially this vampire lair is populated with enemies such as skeevers and feral vampires. This lair must be earned by completing the quest The Scent of Old Death.
It will also become the home of some of the vampires patrons at Volkihar Tavern after the quest The Scent of Old Death is completed. Theoden, Brom, Tish, Wednesday, David and Doc will all begin to travel out to the Secret Sewer around 4 AM each morning and will travel back to Castle Volkihar at various times after 6 PM.
Because this is originally a dungeon, several containers are set to respawn and are not safe storage. Any barrels or satchels are not safe storage. Only storage named for the player are safe storage containers.
Prior to the quest The Scent of Old Death being completed this vampire lair is populated with enemies.
- Only one chest is safe to use as storage (See picture)
- It is possible to teleport into the Secret Sewer lair prior to starting the associated quest. This could happen if the Dragonborn uses the Teleport Tower West portal to Solitude before going in through its main gates. To fix this, the Dragonborn will need to exit the sewer into Solitude. Once initiated, the quest will then populate the objectives
- An essential skeever named "Ben" habitates inside the sewer. He was supposed to be a follower pet, but the scripting is missing and he is not interactable
- Some of the vampires from Volkihar Tavern cannot make their way back and forth from their home to the castle and seem to loiter in daylight