The Coral Quadrant

VOLTRON: The Denubian Galaxy

The Ruby System*

YADL* - The desert planet where Voltron came face to face with his "evil twin." Their leader, Abi Tohan, attends the summit where it is decided to attack doom.
ORON - The planet that tried to quit the Galaxy Alliance when its people fell under the charismatic sway of General Krueger. Senator Roland called the Voltron Force to Oron to save the day.
SANDELLA* - A made-up name on my part, this is the planet where the Voltron Force met the little Sandpeople.

The Topaz System*

TITUS* - A planet of the Galaxy Alliance that has a representative (named Milan) attend the summit to plan the attack on Planet Doom.
NEEVE* - An ice world where Princess Romelle crashes her stolen Doom Cruiser when she escapes Lotor. Not to be confused with planet Noove (see the Azure Quadrant).
JUNO* - Not much is known about this world except that Pidge is watching a travelogue on it in one episode. In my writings, Twyla's home planet.

The Opal System*

TORRES* - A planet of the Galaxy Alliance, whose representative (Remo) attends the summit to plan the attack on Planet Doom.
PHYLOS - A strange planet with an elliptical orbit of a comet. Mainly in the Coral Quadrant, but for a bit its orbit has to overlap into the Azure Quadrant, because it passes by Arus.
EBB* - The planet Sven was taken to heal after his fight with Haggar and was later captured when it was invaded. Most likely the most advanced planet in terms of medical technology in the Denubian Galaxy.