How to get into Lower Catacombs of Skyreach…

From the entrance to Skyreach Catacombs, run straight through the courtyard and down the stairs. The door at the bottom leads to the lower catacombs.

To unlock the Lower Catacombs door:

• you have to kill the Gravelord and High King Durac.
• The Gravelord is a Bone Colossus at the southern end of the first floor
• High King Durac is a Nede warrior who resides in a chamber on the northern side.
• This is THE best place to farm CP in ESO