The Mundeshwari Devi Temple (also spelled as Mundesvari) is located at Kaura in Kaimur district in the state of Bihar, India on the Mundeshwari Hills. It is an ancient temple dedicated to the worship of Lord Shiva and Shakti and is considered one of the oldest Hindu temples in India. It is also considered as the oldest functional Hindu temple of India. The information plaque erected by the Archaeological Survey of India (ASI) at the site indicates the dating of the temple to 625 CE. Hindu inscriptions dated 635 CE were found in the temple. The temple is a protected monument under ASI since 1915.
The temple, built of stone, is on an octagonal plan which is rare. It is the earliest specimen of the Nagara style of temple architecture in Bihar. There are doors or windows on four sides and small niches for the reception of statues in the remaining four walls. The temple shikhara or tower has been destroyed. However, a roof has been built, as part of renovation work. The interior walls have niches and bold mouldings which are carved with vase and foliage designs. At the entrance to the temple, the door jambs are seen with carved images of Dvarapalas, Ganga, Yamuna and many other murtis. The main deities in the sanctum sanctorum of the temple are of the Devi Mundeshwari and Chaturmukh (four faced) Shiva linga. There are also two stone vessels of unusual design. Even though the Shiva linga is installed in the centre of the sanctum, the main presiding deity is Devi Mundeshwari deified inside a niche, which is seen with ten hands holding symbols riding a buffalo, attributed to Mahishasuramardini. The temple also has murtis of other popular gods such as Ganesha, Surya and Vishnu. A substantial part of this stone structure has been damaged, and many stone fragments are seen strewn around the temple. However, under the jurisdiction of ASI, it has been the subject of archaeological study for quite some time.
It is believed that rituals and worship have been performed here without a break, hence Mundeshwari is considered one of the most ancient Hindu temples in India. The temple is visited by a large number of pilgrims each year, particularly during the Ramnavami, Shivratri festivals. A big annual fair (mela) is held nearby during the Navaratra visited by thousands. The worship of shakti in the form of Devi Mundeshwari in the temple is also indicative of tantric cult of worship, which is practiced in Eastern India.