Halesi Mahadev, also known as Halesi Mahadevasthan, is a sacred Hindu pilgrimage site located in the Khotang district of eastern Nepal. It is renowned for its ancient cave temple dedicated to Lord Shiva. The temple complex includes several natural caves believed to be associated with various Hindu deities. Halesi Mahadev is considered one of the holiest places in Nepal and attracts pilgrims and devotees from across the country, seeking blessings and spiritual solace in its mystical surroundings.