Hogwarts Legacy has 5 Cairn Dungeon Locations. Discovering and completing all Cairn Dungeons unlocks The Intrepid Explorer trophy & achievement. You will do all 5 dungeons as part of main- and side quests, which you need to do anyway to finish all quests for other trophies and achievements.
None of the Cairn Dungeons are missable. You can still do all of them after the story by accepting their associated quests. It’s recommended that you simply focus on completing all Side Quests, you do all Cairn Dungeons automatically along the way without worrying about it. See Hogwarts Legacy All Side Quests Guide.
All Collectibles Overview:
All Cairn Dungeons in Hogwarts Legacy
Cairn Dungeon #1: Main Quest – The Helm of Urtkot
Automatically done in Main Quest: The Helm of Urtkot.
Cairn Dungeon #2: Side Quest – Cursed Tomb Treasure
Automatically done in Side Quest: Cursed Tomb Treasure.
Cairn Dungeon #3: Side Quest – ‘Beeting’ a Curse
Automatically done in Side Quest: ‘Beeting’ a Curse.
Cairn Dungeon #4: Relationship Quest (Sebastian) – In the Shadow of Time
Automatically done in Sebastian’s Relationship Quest: In the Shadow of Time.
Cairn Dungeon #5: Relationship Quest (Poppy) – The Centaur and the Stone
Automatically done in Poppy’s Relationship Quest: The Centaur and the Stone.
That’s all 5 Cairn Dungeons in Hogwarts Legacy. After the last one you will earn The Intrepid Explorer trophy or achievement.
For all other Collectible Types refer to Hogwarts Legacy Collectible Guide.
I’ve completed all of the storylines but still not had the trophy…can anyone help?
Try the tomb of treachery floo at the start of poseidar coast I had missed that one during side quests
Yeah… No… I did all of those quests and didn’t get the achievement
Try the Tomb of Treachery like suggested and enter inside. That is the only way I could get the trophy to pop.