Sanctum of Domination

Sanctum of Domination is a ten boss raid instance, new to World of Warcraft Shadowlands Patch 9.1: Chains of Domination. The raid takes place in Torghast with Sylvanas Windrunner as the final encounter.  It is located in Desmotaeron, the area North of the Beastwarrens in the Maw. 

Ilevel requirements are similar to Castle Nathria, in that the final two bosses will drop higher level loot, and are harder, so therefore will require a higher ilevel, in theory, in order to attempt:

The Sanctum of Domination raid takes place in Torghast where players defeat nine bosses as they climb the tower, and finally encounter Sylvanas Windrunner at the top.

If you're struggling to get to the raid entrance safely, this was posted on Reddit, which may help.