This magnificent relief, carved in the mid-seventh century, measures approximately 30m (100ft) long by 15m (45ft) high. Its huge size and scale is difficult to imagine just from photographs; a person standing on the ground in front of it could barely touch the elephants' feet.
The subject is either Arjuna's Penance or the Descent of the Ganges, or possibly both. In additive cultures like India's, logical alternatives are often conceptualized as "both-and" rather than "either-or."
Arjuna's Penance is a story from the Mahabharata of how Arjuna, one of the Pandava brothers, performed severe austerities in order to obtain Shiva's weapon. The idea, which pervades Hindu philosophy, is that one could obtain, by self-mortification, enough power even to overcome the gods. In order to protect themselves, the gods would grant the petition of any ascetic who threatened their supremacy in this way - a kind of spiritual blackmail, or "give to get." (This meaning of the word "penance," by the way, is specific to Hinduism. Unlike the Catholic rite of penance, it is performed to gain power, not to expiate sin.)
The Ganges story is of the same kind, in which the sage Bhagiratha performs austerities in order to bring the Ganges down to earth. Shiva had to consent to break her fall in his hair, because otherwise its force would be too great for the earth to contain.
The symbolism of the relief supports either story. Furthermore, both stories were interpreted in a manner flattering to the Pallavas; the heroic Arjuna as a symbol of the rulers, and the Ganges as a symbol of their purifying power.
The composition of the relief includes the main elements of the story (left) and scenes of the natural and celestial worlds (right). A natural cleft populated by nagas separates the two halves of the relief. Water was poured down this cleft in order to simulate a natural waterfall (the Ganges' descent). To the left, just above the shrine, Arjuna (or Bhagiratha) stands on one leg, his arms upraised, in a yoga posture. Behind him appears Shiva, holding a weapon and attended by ganas. To the right of the cleft, life-sized elephants protect their young below a scene of numerous other animals and flying celestials, all carved with the greatest vivacity, skill, naturalism, and joyousness.