Irkngthand

West of Windhelm and south of Lake Yorgrim. It can be difficult to find using a map marker. You'll need to rotate the map around to see that it's not actually at the top of the mountain but down to the north of the mountain top.

In the courtyard of the ruin there a number of Bandits and chests to loot. All but one of the entrances to the interior of the ruin have collapsed.

Irkngthand contains giant mushrooms that are non-ineractive objects. Many of Skyrim's mushrooms &amp; fungi can be found growing abundantly the area.

Notable Items

 * Quest Item: The Eyes of the Falmer
 * Quest Item: Skeleton Key

Quests
Irkngthand is the location of a majority of the quest Blindsighted for the Thieves Guild storyline. The player cannot gain entry to the ruin before starting this quest. (Dungeon Lock Outs)

Alchemy Ingredients
Irkngthand is home to an abundance of Alchemy Ingredients. Example: Falmer Ears, Chaurus Eggs, Imp Stool, Blisterwort, Bleeding Crown, White Cap, Skeever Tails, Namira's Rot, Glowing Mushroom, Fly Amanita, Spider Eggs, sometimes Human Flesh and Human Heart, etc.

Bugs

 * When going back through Irkngthand after completing the Thieves Guild quest, the door to the final room will not reopen. The problem is you have to jump off a ledge to get to the final door, leaving you unable to go forward or back. Only solution was to reload last save.
 * (Update) You can attempt to exit if you have the full Whirlwind Sprint shout. Climb on top the chest to the right, then jump on top of the fence, then jump on top of the Falmer hut, then at the very top do a full Whirlwind Sprint shout to the ledge. (Confirmed 360 1/1/2012; PS3 2/29/2012; PS3 3/3/2012)
 * If done properly, you only need the first word of the needed Shout.
 * However, it is possible to get stuck between the top of the hut and the rock wall behind it.
 * Occasionally Karliah will fail to follow you out of the hole in the ceiling and you will not be able to complete the quest.
 * Passing through the ruin can cause significant amounts of framerate lag and, in the worst cases, system instability. No known solution other than simply putting up with it, although the slow response time can make the dungeon frustrating and unnecessarily difficult during the larger battles (EDIT: I was experiencing great lag in this locale alone. I deleted my cache and reinstalled the updates. The lag did not persist).
 * Delvin Mallory refuses to accept the Left Eye of the Falmer (a Larceny Target), whether carried by itself or along with the Right Eye of the Falmer.

Enemies

 * Bandits
 * Falmer
 * Chaurus
 * Dwarven Centurion
 * Dwarven Sphere
 * Dwarven Spiders
 * Mercer Frey

Appearances

 * The Elder Scrolls V: Skyrim