Hive Access Tunnel
Hive Access Tunnel is mostly important because of his Secret World that is accesible via the old ILS (GC) or the Hive Chamber A Secret World.
Normally it is accessible via Hive Transport Area by a violet translator gate (which is used in 100% after getting the Energy tank from Mining Plaza) or via Landing Site.
By using the old ILS you teleport yourself at the lowest point of the room by activating the cutscene trigger.
This Secret World is utilized to either go straight to Agon or skip the entire Splinter Hive section of that area.
It can also be used to get seekers first, but that is currently used by no route in the moment.