Arus

Arus is the home of the Arusian race and the first planet to come under Voltron's protection from the Galra Empire.

It served as the resting place for the Castle of Lions, sheltering Allura, Coran, and the Black Lion for around 10,000 years. The Castleship and its occupants were awakened once Lance, Matt, Hunk, and Pidge arrive in the Blue Lion.

Arus' environment and inhabitants are the same as in canon, and can be found on the V:LD wiki.