The Sthalasayana Perumal Temple, also known as Thirukadalmallai ("the sacred seashore"), is an ancient Vishnu temple in the heart of Mahabalipuram. Unlike the rock-cut monuments and structural temples of the UNESCO complex, this temple is still in active use as a place of worship, with daily rituals and seasonal festivals drawing pilgrims as well as curious visitors.
The presiding deity is Vishnu in a reclining posture (Sthalasayana means "resting on earth"), and the temple has significant connections to the Alvars — the Tamil poet-saints whose devotional hymns form the core of Vaishnava theology in South India. The temple structure has been added to and restored over the centuries and includes a gopuram (gateway tower) in the Dravidian style. Visitors are welcome outside prayer times; modest dress is expected and shoes must be removed at the entrance.