Sentok Nor was a Cardassian Nor-class space station built in orbit of planet Betazed following its occupation by Dominion forces in 2374. Sentok Nor served primarily as a maintenance facility and a Jem'Hadar hatchery, and as the Dominion's strategic command post for the sector. In addition, Sentok Nor was also the base of operations for Dr. Crell Moset's experimental efforts to give Betazoid telepathic skills to the Jem'Hadar.
Sentok Nor was destroyed in 2375 by a Starfleet team including Chief Miles O'Brien, Lieutenant Commander Geordi La Forge, and Commander Will Riker. (TNG novel: The Battle of Betazed)