Primeval Chamber is a type of Azurite Mine (Delve) node that spawns in Primeval Ruins biome.
The node can be re-visited, however, player cannot revisit the room below. The door to the room below is tied to the first instance only. regenerate the node instance will wipe the access of the room
Room below the surface level
The rooms below the surface level of the node, contains the six linked sockets Crafting Bench recipe.
The room is also similar to Ruined Chamber (from Vaal Outpost biome) Delve nodes with light pads that need to be stood on for a few seconds to clear the monsters.
It appears to be a great place to obtain maps due to the possibility for Abandoned Charts chests and can contain 3 or more of these chests in the area.