Category for the known worlds where all the living things seen in the Half-Life universe come from. Trending pages Xen Combine Overworld Earth Moon All items (5) # A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Other C Combine Overworld E Earth M Moon X Xen Category:Xen Categories: Locations Community content is available under CC-BY-SA unless otherwise noted.
