The Keep Depths is an area of Bastion's Keep in Act III of Diablo III. It is divided into three levels.
Bholen is the boss of the depths in Adventure Mode.
Ghom is the boss needed to kill in order to proceed to the Machines of War quest
The Keep Depths Level 2 is the location of Cursed Depths event.
There's a Waypoint in Level 2 and Level 3.