Image: Rebel Wolves / Bandai NamcoNo screenshot of Ambrus's Dungeons yet. This one shows Ambrus (Rebel Wolves / Bandai Namco).
Ambrus's Dungeons are court activities where you break into Ambrus's prisons and decide what happens to the people inside. They count toward his anger, which unlocks the duel with him.
Each dungeon is a guarded outpost holding prisoners. You kill the guards, take the keys and talk to whoever is locked up. Some of the prisoners are not what they seem.
They are three of Ambrus's 14 court activities. Fill his anger meter and The Gilded Gauntlet unlocks. They take longer than the cellars, so fit them in when you have time to spare.