Nunungan, officially the Municipality of Nunungan, is a 3rd class municipality in the province of Lanao del Norte, Philippines. Accordin…Nunungan, officially the Municipality of Nunungan, is a 3rd class municipality in the province of Lanao del Norte, Philippines. According to the 2020 census, it has a population of 18,827 people. Nunungan or Nonongen is the largest municipality in Lanao del Norte in terms of land area. It is home to the Mount Inayawan Range Natural Park.