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(1080p/60fps) Largashbur - Skyrim: Vrulgtar and his Orcs continue their journey to the Orc Stronghold of Largashbur. Before they arrive, they travel through the Ruins of Bthalft and encounter a quick bandit skirmish. After the bandit skirmish, Vrulgtar battles an old orc who is seeking a good death. They then arrive at Largashbur where they find a Giant assaulting the Orc Stronghold, where the Orc Wise woman Atub informs the goings on of Largashbur to Vrulgtar. Atub summons Malacath against Chief Yamarz's wishes, and in the process Malacath demands that Yamarz defeat a giant that is defiling Malacath's Shrine in Fallowstone Cave. Vrulgtar agrees to help Yamarz defeat the Giant in Fallowstone cave, and in Fallowstone Cave ... they enter into Giant's Grove, where Malacath's Shrine is being defiled and within Giant's Grove ... Vrulgtar finds out the vile treachery of Yamarz. While returning to Largashbur, Vrulgtar informs his Orcs that he wishes to obtain fresh ore in Echo Deep Mine. Little does Vrulgtar know, that his little ore run will lead him to Mzubthand and into a new Chapter of his Story.

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Largashbur is an accursed Orc stronghold in the Rift beset by giants. It is located southwest of Riften, against the mountains, east of the Dwemer ruin of Avanchnzel. It contains a makeshift altar to Malacath, adorned with a full suit of Orcish armor and lavender. Chief Yamarz is the acting Chief of the Orc Stronghold of Largashbur

Echo Deep Mine is a location near Riften. Initially, Jalamar will point the Dragonborn to it during the quest An Ancient Gate, to find out about the mercenaries that went in there. This is the only way to access Falskaar for the first time. The location is inhabited by bandits.

Fallowstone Cave is a massive cavern with an exit to Giant's Grove, located in the Velothi Mountains northeast of Riften and a short way north of Lost Prospect Mine.
There is one massive cavern with a couple of small caves and tunnels, one leading to Giant's Grove and the other the way back up from the bottom of the main cavern. Trolls and cave bears typically inhabit the place.

The Dwemer ruin Mzubthand is in the mine's depths. Inside, the bodies of a group of unlucky adventurers that died when the automatons within awakened to protect the portal there lay scattered about.

Mzubthand is a Dwemer ruin located in the depths of Echo Deep Mine. It is accessed during the quest An Ancient Gate

Sources:
http://elderscrolls.wikia.com/wiki/Largashbur
http://www.uesp.net/wiki/Skyrim:Largashbur
http://www.uesp.net/wiki/Skyrim:Fallowstone_Cave
http://elderscrolls.wikia.com/wiki/Fallowstone_Cave
http://tes-mods.wikia.com/wiki/Echo_Deep_Mine
http://tes-mods.wikia.com/wiki/Mzubthand