Sabarimala is a Hindu temple complex located at the Periyar Tiger Reserve in Kerala, India, considered to be one of the holiest in Hinduism. It is the largest annual pilgrimage in the world with an estimated 17–30 million devotees visiting every year. Some estimates put the number of annual visitors as high as 50 million. The temple is dedicated to the god Ayyappan also known as Dharma Sastha, who according to belief is the son of Shiva and Vishnu. The traditions of Sabarimala are a confluence of Shaivism, Shaktism, Vaishnavism, and other Śramaṇa traditions.
The temple is situated on a hilltop amidst eighteen hills at an altitude of 480 m (1,574 ft) above sea level, and is surrounded by mountains and dense forests. The dense forest (Periyar Tiger Reserve) around the temple is known as Poongavanam. Temples exist in each of the hills surrounding Sabarimala. While functional and intact temples exist at many places in the surrounding areas like Nilakkal, Kalaketty, and Karimala remnants of old temples survive to this day on remaining hills.
The temple is open for worship only during the days of Mandalapooja (approximately 15 November to 26 December), Makaravilakku or “Makara Sankranti” (14 January) and Maha Vishuva Sankranti (14 April), and the first five days of each Malayalam month.