The Mahishasuramardini cave, also known as the Mahishamardini mandapa, is found at the southern end of the site (known locally as Yamapuri). Excavated on the eastern scarp of a boulder on the main Mamallapuram hill, above it are the ruins of the Olakkannesvara temple.

According to Ramaswami, the temple is unfinished but what has been carved represents the ultimate in Tamil temple rock art. The cave has many panels, and their narrative follows the Markandeya Purana.

The front of the oblong mandapa is defined by four pillars and two pilasters. One of its original pillars was moved to the nearby Adivaraha temple, and was replaced with an incongruous, plain pillar. Portions of another pillar are damaged. Lions are part of the pillar architecture instead of the vyalas found in other Mamallapuram cave temples, consistent with its Durga theme. Uniquely, the temple’s interior artwork was completed before its facade details, ceiling or floor. Its southern pillar and pilaster are the only ones which have been finished. The temple is an example of parallel construction by multiple artisans.

The mandapa has three shrine cells connected to a central, trapezoidal hall. The floor level of the side shrines are about a foot higher than the central shrine.

In the central shrine is a large rock relief of Somaskanda, with Shiva seated in a Sukhasana (cross-legged) yoga posture and Parvati next to him with the infant Skanda. Behind them are a standing Brahma, Vishnu and Surya.

On the northern wall of the temple hall is the Mahishasuramardini legend rock relief, one the most intricately-carved in the Mamallapuram monuments.

On the southern wall of the hall is a carving of the Anantasayi Vishnu narrative with Madhu and Kaitabha. Both layouts are symmetrical.