Gorgos

Gorgos was the home planet of the Gorgons, located a hundred million light years away from Earth.

At some point in earth's remote past the Gorgons developed technology for travelling between worlds by transdimensional portals. They created a portal to Earth and three Gorgons crossed to Earth, entering Greek mythology. After thousands of years, the last of the three attempted to bring the rest of its kind through so they could bond with humanity and take over Earth. However, Sarah Jane Smith, Clyde Langer and Luke Smith closed the gate. (TV: Eye of the Gorgon)

Behind the scenes
The Gorgons do not resemble those in Greek mythology, which were depicted as female beauties with snakes for hair. One creature which was the mythological Gorgon is thought to have originated on Earth and not the Gorgon Homeworld. (COMIC: The Gaze of the Gorgon)