XTR-686

XTR-686 is a black, rocky planet with a thin atmosphere somewhere in BZPB-108. Dukamu and SMK built a portal here that leads to the Dark Universe, which has been used by numerous DU inhabitants to come through to BZPB-108 since.

History
It used to have a proper name that was given to it by the people who lived there, but was lost when their civilization was destroyed by an unseen force. "XTR-686" is a stock name given by the Galactic Government that stands for "Extraterrestrial planet no. 686". Funnily enough, this designation is the same number the Users assigned to the Dark Universe.