Where is the fifth star ship(beacon/beeping Coffin) at N'Erud?

[Booston]

Is there any in-game hint for their locations?
I just can't find the last one that is not designed to be found.

[Neyreyan_Youtube]

somewhere:P
usually 2 are on the dungeon that opens the area
2 are on the opposite side
1 seems to always be on elevation on a hill