Rura Penthe system
From Memory Alpha, the free Star Trek reference.
Rura Penthe system is a trinary star system of the Klingon Empire. It is home to the penal colony asteroid Rura Penthe notoriously known as "the aliens' graveyard". It is located within 2 sectors of the Federation border and in 2293 it was once the destination of a secret Starfleet mission proposal known as Operation Retrieve. (Star Trek VI: The Undiscovered Country)
