Kailashahar is an nagar panchayat town, the headquarters of the Unakoti district in the Indian state of Tripura located along the Bangladesh border. The Kailashahar was the ancient capital of the Tripuri kingdom.And The history of old Kailashahar is associated with Unakoti, a tourist place reputed for its 7th - 9th century AD stone and rock cut images. A Shiva disciple who started the Tripurabda (Tripuri Calendar), prayed for Lord Shiva in a village called Chhambulnagar on the banks of the river Mau. It is speculated that Chhambulnagar, which is mentioned in Rajmala, was situated near Unakoti Hill. The Prince prayed for Mahadeva in Unakoti. For this some people believe that the previous name of Kailashahar was Chhambulnagar. Some believers thought that Har (Shiva) resides in Kailash. Therefore the place was known as Kailash Har which was later on transformed to Kailashahar. A Tripura king named Adi-Dharmapha ruled here in 7th century. He performed a great yagna with much pomp and gaiety. The name Kailashahar found currency since that time. The main festival in Kailashahar is the durga puja festival that carries between September - October and is where all the kids, elderly and adults enjoy. The city of Kailashahar is also known for its bright festival of lights "Kali Puja". One of the biggest Kali Puja Pandals are hosted in this small city.