[bsftcs]

Algamesh's necklace is in a chest in the second room on the winding tunnel that leads from the transition room (the first room) in the crypt. The door has a level 2 lock, so you may not have opened it yet.

And Stackman says: Yes it is possible to stack one's way up there, but it is not possible to jump over - there is an invisible barrier. The same is the case if one tries to tree surf past the mountain.