Gion was located in the Mempa sector and was the largest of planet Da'Kel II's moons.

Although small, Gion possessed enough gravity and atmosphere for humanoids such as Klingons and Kriosians to be comfortable. It supported plant life, including trees, but otherwise was barren.

In 2300, Gion was used as a staging post for The Thorn members Seryl and Cadik before they launched their isolytic subspace weapon attack against Da'Kel III. While on the moon's surface, Seryl killed Bekk T'Agga and her landing party compatriot from the IKS ho'Pung after they discovered the Kriosian terrorists. (TOS novel: Cast No Shadow)