Killian's Dehiscence is seen at the level of:

Killian dehiscence also known as "Gateway of tears'' M/C site for esophageal tear (perforation) In posterior pharyngeal wall the inferior constrictor muscle is divide into two pa thyropharyngeus and cricopharyngeus. Thyropharyngeus has oblique fibers Cricopharyngeus has Transverse fibers. And that creates a triangular space. This is anatomical week space is known as Killian dehiscence.