Mainit, officially the Municipality of Mainit, is a 3rd class municipality in the province of Surigao del Norte, Philippines. According to the 2020 cen…Mainit, officially the Municipality of Mainit, is a 3rd class municipality in the province of Surigao del Norte, Philippines. According to the 2020 census, it has a population of 28,019 people. It is situated on the north shore of Lake Mainit in the north-eastern part of Mindanao. The word "mainit" literally means "hot". The other local term for "mainit" is "mapaso." Mainit is home to a hot spring, the Mapaso Wellness Resort frequented by locals and visitors from nearby towns and provinces. It is regarded that Mainit got its name from this hot sulfuric spring.