Rakghoul tunnels

The rakghoul tunnels were series of cave and underground tunnels located beneath the surface of various worlds, such as Alderaan, Tatooine, and Corellia, where rakghoul infestations developed. Existence of the tunnels remained unknown until the plague broke out on those worlds. The Hyland Organization for Rakghoul Neutralization used the Spike to breach the tunnels and allow their forces to combat the infection.

Text and facts from the “Rakghoul tunnels” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.