Droog

Droog was the capital city of the Ethereals' homeworld. Its buildings were made of crystal. Droog was taken over by the Baggolts after they had rebelled against their masters. The First Doctor and a group of Ethereals led by Mitzog disguised themselves as Baggolts to enter Droog and break into the control centre, where the Doctor used a switch on the master panel to end the Baggolt rebellion. (DWAN: The Cloud Exiles)