Descent of the Ganges, known locally as Arjuna's Penance, is a monument at Mamallapuram, on the Coromandel Coast of the Bay of Bengal, in the Chengalpattu district of the state of Tamil Nadu, India. Measuring 96 by 43 feet, it is a giant open-air rock relief carved on two monolithic rock boulders. The legend depicted in the relief is the story of the descent of the sacred river Ganges to earth from the heavens led by Bhagiratha. The waters of the Ganges are believed to possess supernatural powers. The descent of the Ganges and Arjuna's Penance are portrayed in stone at the Pallava heritage site. The relief is more of a canvas of Indian rock cut sculpture at its best not seen anywhere else in India. It is one of the Group of Monuments at Mamallapuram that were designated as a UNESCO World Heritage Site since 1984.

Mamallapuram, is a town in Chengalpattu district in the southeastern Indian state of Tamil Nadu, best known for the UNESCO World Heritage Site of 7th- and 8th-century Hindu Group of Monuments at Mahabalipuram. It is one of the famous tourist sites in India. The ancient name of the place is Thirukadalmallai. It is a part of Chennai Metropolitan Area. It is a satellite town of Chennai.