What is "cadmea"

The Cadmea, or Cadmeia ( Greek: Καδμεία), was the citadel of ancient Thebes, Greece, which was named after Cadmus, the legendary founder of Thebes. The area is thought to have been settled since at least the early Bronze Age, although the history of settlement can only be reliably dated from the late Mycenaean period (c. 1400 BC).