This level difficulty jumps a bit compared to the previous level (Enchanted Labyrinth). There is an NPC right at the beginning of the level. You should try to complete quests from this NPC because the rewards are good (one is an artifact and another is 3 more vault slots).
There are Golems and skeleton mages everywhere here. There is also a warp spot to fight a boss. There is nothing special with this boss. You could get Pure Golem fragment dropped from it but it is not worth killing it at this point. If you want the fragments, you better off doing daily dungeons.
There is another locked door with a skull head next to it. Again, you will need 2 gems to unlock the door. Both gems can be found in this dungeon level. Search through out the level for them.
There is only one puzzle that you need to solve. There are 4 levers and you need to flip them all under a certain limit of time. *hint* Learn about their locations and how each behaves.
After you open the door with 4-lever, you should be on the way to the next level.