Re: diachi
In Brightwood. If you go ontop of Garth's Tower there's a cullis gate. If you jump off the broken part of the railing ajacent to the gate you'll fall into a hole. Follow the tunnel doing the puzzles as you go, at the top you get a pretty sweet augment, but more importantly after getting to the top you'll come out to a legde with a chest. Inside you'll get a sparkling katana with a name I can't remember (found in a different post)
[Copy pasted from a post in a sticky from the Help Section]