Удджайни, also known as Ujjain, is a city in the Indian state of Madhya Pradesh. It is one of the seven sacred cities in Hinduism and is famous for the Mahakaleshwar Jyotirlinga, a revered temple dedicated to Lord Shiva. Ujjain is also known for hosting the Kumbh Mela, a major Hindu pilgrimage that occurs every 12 years, attracting millions of devotees. The city has a rich historical background, with references dating back to ancient texts like the Mahabharata and Puranas. Ujjain was once a significant center for astronomy and education, home to the ancient observatory, Jantar Mantar. Today, it remains a vital cultural and religious hub in India.