Mzinchaleft

Mzinchaleft is a Dwemer ruin located south-west of Dawnstar in The Elder Scrolls V: Skyrim. It is involved in both a Dark Brotherhood quest, as well as a miscellaneous side-quest acquired in Falkreath. The Gatehouse of Mzinchaleft houses an entrance to Blackreach. It is accessible through the main quest.

History
Mzinchaleft shows the ancient struggle between the Dwemer and Falmer; and how the Falmer now lurk in their former master's ruins, still killing off Dwarven sentients and constantly preparing for their war against the light dwellers.

Quests

 * Grimsever for Mjoll the Lioness in Riften
 * Access to Blackreach
 * Arniel's Endeavor

Enemies
The outer level of Mzinchaleft consists of Bandits, whom have taken up residence finding artifacts for their benefactor, whom is only paying per item.

After that, the Dragonborn faces Dwarven sentinels. Dwarven Spiders and Spheres are encountered on the first level. The Mzinchaleft depths consist of several Falmer, two Chaurus, and one Falmer Gloomlurker.

To get to the final room, a series of levers must be toggled in order to enter. This puzzle is made much easier using Slow Time Dragon Shout, to run past the moving bars.

In the final room, the Mzinchaleft Gatehouse (which also contains the passage to Blackreach), the player is required to fight a Dwarven Centurion (leveled) and a Dwarven Sphere. At which point, without the required quest item, the player may only return to the surface via a lift directly to Skyrim. Here they can pull a lever to permanently unlock this quick route for future use.

Loot
Dwarven and Falmer artifacts are extremely heavy, and so it is recommended to clear the dungeon and then return to finish looting by the quick access lift made available via the Gatehouse.

The Dwarven Spiders and Dwarven Sphere Guardians are treasure troves for soul gems, Dwarven Oil, gems and Dwemer mechanical parts. They are also known to drop Dwemer Cogs, which are a related quest item.

On the exterior is a Mzinchaleft Work Order and the interior holds Maluril's Journal. The journal is behind the locked door which will be found directly after receiving Maluril's Key from a Bandit.

The ground floor water in the depths provides access to submerged dungeons just past the staircase on the South East side of the room. A table is viewed in the first room, with Dwarven Oil. There are two chests in the cell to the left, one small chest on the left containing a Siver Amethyst Ring and Necklace of Minor Smithing and one larger chest on the right containing Gold, Garnet, Silver Garnet Ring, Hide Boots and Dwarven Oil. To the top right of the stairs, where the Centurion Grandmaster is encountered, there is additional loot.