Sacred places in Gaya correspond to physical features, most of which occur naturally. Ghats and temples line the banks of the sacred Falgu River. Trees such as pipal trees and Akshayavat, the undying banyan, are especially sacred. The Mangla Gauri shrine is marked by two rounded stones that symbolize the breasts of the mythological Sati, the first wife of Lord Shiva. The most popular temple today is Vishnupad Temple, a place along the Falgu River, marked by a footprint of Vishnu incised into a block of basalt, that marks the act of Lord Vishnu subduing Gayasur by placing his foot on Gayasur’s chest. The present day temple was rebuilt by Devi Ahilya Bai Holkar, the ruler of Indore, in the 18th century. Buddhist tradition regards the footstep in the Vishnupad Temple as a footstep of Buddha (who is regarded as an avatar of Vishnu by Hindus). Gaya is significant to Hindus from the point of view of salvation to the souls of ancestors (a ritual called pindadanam). According to Ramayana, when Lord Rama came to Gaya along with Sita for pitrupaksha (or to perform pindadanam), Sita cursed the Falgu River following some disobedience on the part of the river. The mythology states that on account of this curse, Falgu River lost its water, and the river is simply a vast stretch of sand dunes. For Buddhists, Gaya is an important pilgrimage place because it was at Brahmayoni hill that Buddha preached the Fire Sermon (Adittapariyaya Sutta) to one thousand former fire-worshipping ascetics, who all became enlightened while listening to this discourse. At that time, the hill was called Gayasisa.