Sabarimala is a Hindu pilgrimage centre located at the Periyar Tiger Reserve in the Western Ghat mountain ranges of Pathanamthitta District, Perunad grama panchayat in Kerala. It is one of the largest annual pilgrimages in the world, with an estimated over 100 million devotees visiting every year. Ayyappan's temple is situated amidst 18 hills. The temple is situated on a hilltop at an altitude of 1260 m (4,133 ft) above main 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.