The Hidden Path is an extended side quest taking place across all four acts of Grim Dawn.
Grim Dawn: The Hidden Path Quest
To unlock secret area in Act1 Lower Crossing you need Dynamite (2).
After killing Guardian of Dreg (poison dmg) you obtain an item called Runestone of Dreeg. With this item you can open second secret place in Act 2.
Best place to farm Dynamite?
- Act2: Moneybags Martin in Cronley’s Hideout drops one dynamite, every time.
- Staunton Mine has one guaranteed Dynamite.