In the province of Skyrim, there are several dungeons that are not open to the Dragonborn to begin with. Some are heavily based in quests and so to prevent the player from breaking the quest, the player needs to have them active for the dungeon to be available.
- Avanchnzel: Unfathomable Depths
- Dustman's Cairn: Proving Honor
- Irkngthand: Blindsighted
- Korvanjund: The Jagged Crown
- Snow Veil Catacombs: Speaking With Silence
- Twilight Sepulcher: Darkness Returns
- Ysgramor's Tomb: Glory of the Dead
- Saarthal: Under Saarthal
- Mzinchaleft Gatehouse: Discerning the Transmundane
- Ustengrav: The Horn of Jurgen Windcaller
- Bthardamz: The Only Cure
- Mzulft: Revealing the Unseen
- Labyrinthian: The Staff of Magnus
- Blackreach: Discerning the Transmundane
- Knifepoint Mine: Boethiah's Calling (The section of the mine with the Champion is cut off by a cave-in unless the player starts the quest.)
- Gyldenhul Barrow: DeathbrandDB
- Kolbjorn Barrow: UnearthedDB
- Vahlok's Tomb: Lost LegacyDB
- Note: The list is not complete.
On PC, it is possible to hit the tilde (~) key and type "tcl" to toggle noclip and move through the barriers. From here you can explore the dungeon as normal. Note that this defeats the purpose of the wall and will most likely break the quests that pertains to it.
Also several of the locations can be entered from the hidden "exit". Using a collision glitch on consoles will open most areas.