The third noble Truth, the cessation of dukkha, is nibbana. At the attainment of enlightenment nibbana, the unconditioned reality, is experienced. Citta, cetasika and rupa are conditioned realities which arise and fall away, they are dukkha. Nibbana is the ultimate reality which is unconditioned, it does not arise and fall away, it is not dukkha. Nibbana is the end of unsatisfactoriness inherent in all conditioned realities which arise and fall away.