Well, that’s the Volcano area in general, but I’m not here to debate your outpost location decisions, I’m just saying what I found out about the current purge situation and how you can avoid teleportation of the purge.
This can be also use the other way around, for example, I know where they teleport in my place, and it’s always the same spot, so I close it with no roof, put 5 thralls inside this room with Truncheons and I interrupted every wave. They all teleported there, the thralls knocked them all out, including the names, and I just keep/kill what I wanted, without any lost at all. Now there is always and elite that spawns that can’t be knocked down on one of the waves, this guy I let be, so my guard killed him at the normal entrance.
So in a sense Funcom broke purges but made them 100 times easier, if you pay attention and manage to adapt quickly.