According to Puranas, Varanasi was founded by Shiva. Varanasi also known by its former names of Banaras and Kashi, is a city on the left bank of the Ganges river in the southeastern Uttar Pradesh state of northern India. It is the holiest city in Hinduism and one of the world's oldest continually inhabited cities. Kashi, its ancient name, was associated with a kingdom of the same name 2,500 years ago. The Lion capital of Ashoka at nearby Sarnath has been interpreted to be a commemoration of the Buddha's first sermon there in the fifth century BCE. In the 8th century, Adi Shankara established the worship of Shiva as an official sect of Varanasi. Since ancient times, the city has been an important center of Hindu devotion, pilgrimage, mysticism, and poetry contributing to its cultural importance. The location at the confluence of the Ganges and Yamuna rivers has been known in ancient times as Prayaga, which means place of sacrifice in Sanskrit. It was believed that God Brahma performed the very first sacrifice in Prayagraj. The word prayaga has been traditionally used to mean "a confluence of rivers". Prayagraj denoted the physical meeting point of the rivers Ganges and Yamuna in the city. An ancient tradition has it that a third river, the invisible Sarasvati, also meets there with the two. Today, Triveni Sangam (or simply Sangam) is a more frequently used name for this confluence. This yatra is considered the most enlighting one ever.