The temple is considered as the ‘oldest Functional' temple of the world as rituals have been performed here without a break.

Maa Mundeshwari Devi Temple is dedicated to Lord Shiva and Shakti and is positioned in the Mundeshwari Hills. The temple also has deities of Ganesha, Surya and Vishnu. The Archaeological Survey of India (ASI) dates the temple to 108 AD and has been a protected monument since 1915. Mundeshwari Temple is the oldest specimen of the Nagara style of temple architecture.

Around the seventh century AD, Shaivism became the prevalent religion and Viniteswara, which was a minor deity, emerged as the presiding deity of the temple. The Chatur Mukhalingam (Lingam with four faces) representing him was accorded the central place in the temple, which it holds even now.

After this period, the Cheros, a powerful aboriginal tribe and the original inhabitants of the Kaimur hills, ascended to power. The Cheros were worshippers of Shakti, as represented by Mundeswari, also known as Maheshmardini and Durga. Mundeswari was made the main deity of the temple. However, Mukhalingam still occupied centre stage in the temple. So, the image of Durga was installed in a niche along one wall of the temple, where it resides to this day, while the Mukhalingam survives as the subsidiary deity, though in a central position.

It is believed that rituals and worship have been performed here without a break; hence Mundeshwari is considered one of the most ancient functional Hindu temples in the world. The festivals of Ramnavami and Shivrartri hold special charm at the Mundeshwari temple and the temple is visited by a large number of pilgrims each year, to soak in the spiritual glory.