|# of Zones||5|
|Respawn Time||10 days or 30 days|
|Falmer, Dwarven Automatons, Frostbite Spiders|
|Console Location Code(s)|
|NchuandZel01, NchuandZel02, NchuandZel03, NchuandZel05, NchuandZel06|
|Understone Keep (Markarth)|
|# of Iron||4|
|# of Corundum||1|
|# of Moonstone||1|
Understone Keep, the castle in the city of Markarth, comprises the exterior portions of Nchuand-Zel, which is actually a cavernous Dwarven castle carved deep into the mountain and being excavated under the direction of Calcelmo. There is enough scrap metal in Nchuand-Zel to make almost 400 Dwarven metal ingots.
 Related Quests
- Nimhe, the Poisoned One: Kill the giant frostbite spider blocking access to Nchuand-Zel.
- The Lost Expedition: Recover the journals from the expedition in Nchuand-Zel.
 Nchuand-Zel Excavation Site
This area consists of a corridor running through two connected, square rooms, each with stone staircases on all sides. All staircases are blocked by crumbled stone except the one on the far left, which provides access to an area clearly being excavated. In the first chamber, in addition to the dwemer metal items and scrap lying around, there will be an unlocked chest at the top of the stairs and rubble opposite the door you unlock with the key.
Follow the excavated path to the next room. There are two stone pillars in the relatively large cavern, along with excavation scaffolding that you descend. The shorter of the two has a respawning Dwarven dagger, a blacksmith's draught, and a piece of bent Dwemer scrap metal on it. You can jump on it from the ledge near the cart. There is a small unlocked chest in this room which utilizes Whirlwind Sprint to access; Jump from the ramp leading down into the room onto a large wooden structure in the northwest corner. Then, climb up the rocks sticking out of the wall until you can't climb any higher, and then Whirlwind Sprint across to the crippled stonework ledge. The chest will be to your right. Technically, you can reach this chest without Whirlwind Sprint, but it requires dubiously climbing onto and around a fallen stonework cube on the ledge or careful jumping and using Silent Roll to bypass the stonework cube.
Three frostbite spiders precede a giant frostbite spider named Nimhe, who has nested in a large hole in the ceiling immediately adjacent to the entrance to Nchuand-Zel. Nimhe is the target of the quest Nimhe, the Poisoned One.
Nchuand-Zel consists of a giant interior space with a central tiered walkway that provides direct access to Nchuand-Zel Quarters and Nchuand-Zel Armory, and indirect access to Nchuand-Zel Control (actually you can directly access control by standing on the raised cement slab near the cavern entrance and jumping to the rocky ledge just nearby, and using a little bit of stafe to get up the last bit). The floor of the central room is flooded, and much of the bottom walkway has crumbled, making navigating the room a bit difficult. Falmer have occupied the entire space, and can be found in the central room and in each of the three interior zones (see below).
A new quest, The Lost Expedition, becomes available upon discovering journals on the corpses of Markarth mages that had ventured into Nchuand-Zel against Calcelmo's advice. This quest provides the opportunity to re-activate Nchuand-Zel's automated defenses.
On entering you will be going down a ramp. At the bottom is a trap. Turning left, you will see it leads you into a wide open space with ramps. Directly ahead and halfway to the first portico will be a Falmer. You will see several doorways at different levels to your right but ignore them for now. The first portico has a ledge to the left with a Falmer on it. With high sneak, this Falmer may fall off the edge if you take out the first with a bow. The ledge can be used to take out the remaining Falmer. Past the first portico, the path continues to a second portico that has three levels; you are on the top level. To the left, another Falmer is standing in front of the brass object and may be difficult to see. There is a door to the left of that Falmer which is your target point (Quarters) after clearing this room. A ramp circles downward from the back of the top portico to the second level and another ramp goes from the second level to the lowest level. On level two of the second portico is another Falmer (on the lowest level is a locked door with a chest) and following the ramp on the second level to the left is a third portico with another Falmer. If you continue past this farthest left portico the ramp enters the water. Just next to it (as you are now facing it will be to your right) is a door with a few potions.
As previously mentioned there is a doorway to the Quarters on the south side of the top level To the west there are four doorways. The southern door has no ramp and is accessed through the Quarters section. Moving south to north there is a doorway on the lowest level to the Armory. the next door is on the second level which is the exit from Armory and allows access to the farther northern door to the Control section. Egress back to the ramp is via a ledge just north of that door.
The normal mode is to clear out the main room then start at the Quarters, go to the lowest level and exiting back to the main room to get to the Control section. It is however possible, not advisable, to jump onto the exit ledge and do things differently or use this as a faster way when doing multiple loot trips.
 Nchuand-Zel Quarters
On entering there is a small alcove to the left with various Dwemer items. Go straight ahead and turn right to see your first Falmer but be careful, down the steps is a second one just out of sight. Take these two out. You can now go down the steps or straight ahead. It does not matter which direction you take first.
 Steps Downward
You will end up in an area that has two dead Falmer, a set of stairs and a live Falmer on the steps. There is a magic trap at the top of the steps and two Falmer, one with a companion just beyond. It's possible to take out the one on the steps and have the others race into the magic trap killing one often and damaging the second one and possibly the companion as well. You'll be able to see a tree at the top of the steps and right. The Falmer with the companion hang out here if not killed by the trap. If the magic trap is not sprung by the Falmer, hang as far right as possible to skate past this trap. There is a table ahead with Strom's diary on his body and a dead Falmer to the right. If exploring the tree be careful, there is another magic trap. From the stairs you can go left or straight ahead. Going left, right, left down some short halls you find another Falmer in what looks like an office or family area with a dining room straight across from it. Be sure to get the Dwarven shield on the wall. Past this area is a giant frostbite spider in what would be the bedroom. There is a chest here. Go back to the stairs then left (toward the table). There is another dining room, various loot to the right and continuing on then turning left several dead Falmer and an Imperial soldier's body. The chamber beyond is a torture chamber with little loot and a lever to the left of the entrance. Go ahead and pull the lever.
 Straight Ahead
Continue down the hall (note the crumbled wall; you can use this to get the Falmer mentioned later past the cluster of Falmer) and it turns left where another Falmer is. Just before you go down the stairs turn right for a locked treasure room with a chest. Continuing down the stairs you will see four Falmer clustered together. High sneak and bows work wonders here as well as Frenzy spells. Past them turn right and there will be a set of stairs going up. At the top and to the left is a Falmer with a companion and to the right another Falmer (these are the guys you can see through the broken wall). Turn right at the top of the stairs for more stairs then turn left down a ramp. At the bottom of the ramp is a door back out to a ledge in the main ruins with a chest. Coming back inside turn right as your now facing for another room with a last Falmer. Turn left in this room for a final room with a chest.
 Nchuand-Zel Armory
Entering you will see a stairway straight ahead, a passage to the left, and a ledge above this passage. There is a Falmer on the ledge and another at the top of the stairs to the right just out of sight. The hallway has a few Dwemer goods but otherwise leads to a locked door that's not needed. At the top of the stairs turn right and at the top of another set of stairs is a Falmer with a companion walking the passageway left to right as your facing. Go to the left first but watch out for the trap at the top of the stairs. Turn left for another trap then enter the main chamber. This is where the locked gate is and the reason you can avoid it.
To your right, you will see several inactive Dwarven automaton on pedestals. There are two wall-mounted circular openings, one on either side of the room, from which a leveled Dwarven automaton can spawn. They do not spawn if you sneak past the openings. The first gate is open and has various loot and a chest. The second gate has an adept lock and contains a full set of Dwarven armor. The third gate has a expert lock and a chest, and the final gate is open with only a few plates. At the foot of the centurion is Erj with his diary and nearby a dead Falmer.
Now return back to where the first trap was and keep going up those stairs. The doorway takes you to the ramp that leads to the Control section.
 Ramp to Control
On this ramp you will find two soldiers and Krag with his diary as well as an inactive centurion. At the top of the ramp is the door to the Control section but to the right is the ledge back to the entrance. Along this ledge is a moonstone ore deposit. (Tip: To hop onto this ledge from the entry point start near the wall not the edge.)
 Nchuand-Zel Control
When you enter the Control section, there will be two alcoves on either side with Dwemer items. Moving along the hall, it turns left then right up a ramp. There is a trap here and at the top a Falmer you can see and a hidden one further up. Turn left at the top and you'll see a long hallway with a trap in the middle and two Falmer at the end. Near where the Falmer are and to the left is a table, an apothecary's satchel and just to the right of the table a chest. Turn left to continue and find Staubin with his diary. Follow the stairs upward and counter-clockwise around to a table with some items on it. Two Dwarven spheres will emerge to attack you. Continue onward taking a right then left up the stairs to the final room to your left with a Falmer guarding a lever, various goodies and a chest.
The lever engages the Dwarven security and finishes the quest. There will be a battle between Falmer and automatons on exiting to the main room. This does not make the Dwarven automatons in the Treasury room active. The lever also opens the gate to the right as you enter the room. Follow this hallway down and it turns right. At the end is another chest. To exit backtrack to the first turn left but turn right and hop down to the entry point.
On exiting to the main room a battle is underway and the first thing you will see is the centurion now active fighting some Falmer. To your left is a column you can use to hide behind and let them battle it out. It's also a good position to take on the centurion, who nearly always wins, if you wish to. The abundance of Falmer usually results in them winning most of the other battles going on around the room. Deal with them as you see fit and you're done. To avoid fighting at all, there is a natural overhang to the left of the door which will take you back to the bridge at the start.
- Nchuand-Zel has a small number of mini-Falmer that appear after the automated defenses have been turned on during the Lost Expedition, when the player returns to the chamber. They are about 60 percent of the size of their normal brethren, but just as powerful.
- The first iron ore vein is situated in the chamber with the two stone pillars; it is found near the bottom of the earthen ramp in the western corner of the chamber.
- The second iron ore vein is in the same chamber at the top of the wooden ramp, next to three barrels.
- The third iron ore vein is in the tunnel heading south leading from this same chamber, on the floor, on the inside of the bend as the tunnel bears east, just after the first frostbite spider.
- The final iron ore vein is on the right hand wall of the tunnel just before it opens out, not far from the third ore vein.
- The corundum ore vein is past the three frostbite spiders, on the floor, near a stone pillar and a lootable spider egg sac.
- The moonstone ore vein is on the wall as you follow the earthen ramp back to the exit in the main chamber.
- In the central cavern there is a copy of the Alteration skill book Sithis.
- Access to the excavation site is obtained either by picking the lock, or by receiving the key from Calcelmo as part of the quest to kill Nimhe.
- If you stop just short of pulling the final lever, after 60 days (the test point, although 30 should be enough) the items (Dwemer loot, potions, mines, etc.) will reset in some sections but not others. The named dead NPC's bodies will be removed.
- In the Excavation, the ordinary spiders will not reset, but Nimhe, the dead Legionnaire soldier, loot, and mines will reset. (You may have to get these on the return since there is a glitch where mines don't always reset correctly.)
- In the Main Chamber, the Falmer will not reset but the loot will, as well as the chest on the south ledge accessible through the Quarters section.
- In the Quarters, the Falmer will reset but not the loot or chests.
- In the Armory, the Falmer and loot/chests reset.
- In the Control, the Falmer reset but not the loot nor the Dwarven spheres. Final treasure will still be intact.
- In the Armory, after looting the chest by Erj and killing the two Dwarven automatons that spawn, they will be unlootable.