Nalogen is a star system located near the edge of the Milky Way Galaxy's Alpha and Beta Quadrants, on the exterior of the galactic barrier. The fourth planet of the Nalogen system, planet Nalogen IV, was the site of a Kelvan enclave that was colonized in the late 23rd century. (TOS episode & Star Trek 6 novelization: By Any Other Name; TNG - Pantheon novel: The Valiant)