A month-long fair in every three years is held at Matsya Narayan Temple of naturally and culturally enriched village of Machhegaun situated 8 km south-west from the center of Kathmandu city. “Matsya” is a Sanskrit word denoting the avatar of Lord Vishnu in the form of fish whereas “Narayan'' is another name for Lord Vishnu.  Located in the lap of beautiful Chandragiri hills, this temple is evidently said to be built 500 years ago. This exceptional festival falls on an additional lunar month happening only once in every 3 years, which is given the name of “Malamass” as per Hindu religion.  As per the Gregorian calendar, this festival mostly falls between the months of April and July. As per the Astrological calendar, this religious festival takes place during Shravan Shukla Pratipada to Shrawan Krishna Aunsi. Hindu devotees from Nepal as well as India along with their family pay visit to the temple. 

Lord Vishnu as "Matsya"

It is said that during the era of Satya Yuga, people were becoming irreligious which forced Lord Vishnu to renovate the earth and mankind with a great flood.  By creating guidelines for new humankind in Vedas (4 Hindu religious scriptures) he handed over them to Lord Brahma. While Lord Brahma was taking a quick rest, a demon named Hayagriva took an advantage to steal away the Vedas and to hide himself deep down into the ocean. During that time, a King named Satyavrata, a great devotee of Lord Vishnu used to worship Lord Vishnu regularly with the hope to meet him. Lord Vishnu, happy with his devotion, paid a visit to the King. 
Following the story, it is mentioned in the popular legend of Matsya Purana that the king Satyavrata was pleaded by a small fish in a river for help. He kept the fish in Kamandalu (an oblong water pot) where he observed that the size of the fish was gradually increasing. The King shifted the fish to a pond and later to the sea as the size of the fish was still increasing. Then the fish revealed itself as the incarnation of Lord Vishnu and alerted the King that within seven days a great flood would occur causing destruction of mankind. Lord Vishnu ordered King Satyavrata to build a boat to carry medicinal herbs, seven saints, and animals like Basuki (King of Serpents). At the occurrence of the great flood, the boat was protected by Lord Vishnu as he turned into Matsya avatar and killed the demon Hayagriva handing the Vedas back to Lord Brahma. With this folklore, King Satyavrata also named Manu is taken as the first man of this era of humankind. 

Happenings During The Fair 

The whole month celebrated is highly dedicated towards Lord Vishnu who is regarded as the principal deity for the preservation and maintenance of the universe. During the fair of Purushottam Mela, devotees take a dip in the pond which surrounds the temple with a faith to be free from all the sins of their lives. One of the major attractions of the festival is the fair's market of local delicacies, handicrafts, and souvenirs. The visitors are offered varieties of products at a very affordable price which invites even more people. Devotees chant holistic mantras and bhajans in the name of Lord Vishnu keeping up with their fasting being loyal to Lord Vishnu. For the whole time period of Malamass, Narayan Pooja also called Purushottam Mahatmya is held in the premises of Matsya Narayan Temple. Worshiping the fish avatar of Lord Vishnu, devotees restrain from consuming fish for the entire month. The period of “Malamass” is not considered as a favorable time frame for festivals and auspicious activities.