Mahakaleshwar Mandir is a famous Hindu temple dedicated to Lord Shiva, located in the city of Ujjain, Madhya Pradesh, India. It is one of the twelve Jyotirlingas, which are sacred shrines of Lord Shiva and are considered some of the holiest pilgrimage sites for Hindus.

The temple has a rich history and is believed to have been built during the Gupta period (around the 4th to 6th century). It holds great significance in Hindu mythology, as it is believed that Lord Shiva in the form of Mahakal is the eternal timekeeper and protector of the universe.