Kannaga is a strategically important Klingon world.
Kannaga is a metal-poor planet that was of immense value to the Klingons due to its proximity to Federation territory. The closest major base that the Klingons had to the Federation was located at Kannaga, and therefore many Klingon colonists were sent to that world. The colonists established cities that over the years grew quite large. Heavy patrols were maintained in the area, and the Klingons intercepted any ship that entered the system.
The Klingons had 7 battle groups based at Kannaga in the 23rd century, and rotated more through the planet on a regular basis. Large numbers of ground troops were normally based at Kannaga, and a significant amount of the planet's surface is used for training. (FASA RPG module: The Klingons: Game Operation Manual)