unbelievable (adj)

The noise was unbelievable.
The magician's performance left the audience in awe, prompting whispers of "unbelievable."
Witnesses described the scene as unbelievable, unable to comprehend the magnitude of the natural phenomenon.
The sudden turn of events in the plot was so unexpected that it felt unbelievable.
Science often explores phenomena that were once considered unbelievable or supernatural.