Where do I find the four chests needed to open the Final Chest?

No screenshots since I complete the game and uninstalled, but from memory:

1. To the right of the Legion quartermaster building (between it and the wall)
2. In the initial cave area of Hieberheim (don't recall exactly where it was)
3. At the end of a puzzle in a cave south of Sacred Stone
4. In the bushes behind the Wizard's House in Hunter's Glen

Theres a +Ability and a +Stat book inside (same as the ones from the Teller of Secrets) as well as a bunch of orange loot (not sure if leveled, I opened it at L20 and got L20 gear).