Mumbai is the most populous city in India. Mumbai is built on what was once an archipelago of seven islands: Bombay Island, Parel, Mazagaon, Mahim, Colaba, Worli, and Old Woman's Island (also known as Little Colaba). Some of the oldest edifices in the city built are, Jogeshwari Caves, Elephanta Caves, Walkeshwar Temple, and Banganga Tank. The Elephanta Caves are a network of sculpted caves located on Elephanta Island or Gharapuri (literally "the city of caves") in Mumbai Harbour, 10 kilometres to the east of the city of Mumbai. The island was a Hindu place of worship until Portuguese rule began in 1534. This cave was renovated in the 1970s and was designated a UNESCO World Heritage Site in 1987. Described as a "masterpiece of Gupta-Chalukyan art", the most important sculpture in the caves is the Trimurti, carved in relief at the back of the cave facing the entrance, on the north-south axis. It is also known as Trimurti Sadashiva and Maheshmurti. It is 20 feet in height. The cancellation depicts a three-headed Shiva, representing Panchamukha Shiva (Trimurti).