Blackreach is a large underground cave full of dwarven ruins and bioluminescent plants. It can be accessed via three Great Lifts and by going through several other Dwemer ruins, including Alftand, Mzinchaleft and Raldbthar.
Places
Debate Hall
A small Dwemer ruin containing Falmer and Falmer Servants.
Derelict Pumphouse
A small Dwemer ruin.
Farm Overseer's House
A small empty dwemer house and mushroom farm north-west of the Tower of Mzark.
Hall of Rumination
A small Dwemer ruin containing Falmer.
Pumping Station
A Dwemer area containing Falmer.
Raldbthar Deep Market
A Dwemer ruin located on the mountains slightly south-west of Windhelm, between Lake Yorgrim and the White River.
Reeking Tower
A zone of the Blackreach dungeon found under the Dwemer ruin Alftand.
Tower of Mzark
Tower of Mzark
An abandoned Dwemer tower. This tower leads to a large chamber where there is another Dwemer Oculory. This one contains an Elder Scroll. Also in the tower are the following:
- a copy of Mystery of Talara, v1
- a copy of The Armorer's Challenge
- a Scroll of Muffle
Initially, the only entrance to the tower is within Blackreach, but once exited using the lift, it can be accessed from Skyrim.
Outside the tower: bed roll ×3 and knapsack ~940 
value (L58).
Quests
Silent City Catacombs
A Dwemer area containing Falmer.
Silent Ruin
A small abandoned dwemer ruin found in Blackreach, north of the Pumping Station. Inside can be found:
- A copy of the book Warrior.
- One Crimson Nirnroot
War Quarters
A small Dwemer building in Blackreach.
Sinderion's Field Laboratory
Sinderion's Field Laboratory
Sinderion's research station. Inside can be found the following:
- Sinderion's Field Journal and a copy of De Rerum Dirennis.
- An Attunement Sphere, cooking pot, alchemy lab, arcane enchanter and stone bed.
- Potions ×3, chest ~800; knapsack ~120
value (L66). - Many alchemical ingredients, including a Daedra Heart, Eye of Sabre Cat, Ice Wraith Teeth, Luna Moth Wing, Honeycomb, Black Soul Gem, Greater Soul Gem and Crimson Nirnroot ×2.
Also, right outside the structure, near the door, is an Ebony Ore Vein.
Quests
Items of Note
The cave is significant source of ore:
- Iron Ore, Gold Ore, Corundum Ore ×2, Orichalcum Ore Vein ×3, Quicksilver Ore Vein ×3, Gold Ore Vein ×2, Moonstone Ore Vein, Ebony Ore Vein ×4, Corundum Ore Vein ×13 and Geode Vein ×32.
- Crimson Nirnroot ×44 and Chaurus Eggs ×31.