Arrival paths can be created via the Paths Menu, or just named with the word "Arrival".
If an arrival path does not exist, the player will appear in the area at the same location in relation to the origin of the area, that they were when last in an instance of that area. Or, if they were never in that area before, they will appear at the 0,0,0 origin.
The behavior of Arrival paths is handled in script, so can be modified. For example, it is possible to modify how the arrival system works, depending on whether the player is entering the area for the first time, or has previously been in the area.