Zebadee

Zebadee was a planet used as an intellectual meeting place. When the Second Doctor visited Zebadee with John and Gillian, he learned from Madam Rosa that he would soon encounter deadly robots. Realising that he would have to leave his grandchildren to keep them safe, he convinced them to enrol at the university on Zebadee, then travelled on alone. (COMIC: Invasion of the Quarks)