Papua New Guinea is one of the most culturally diverse countries in the world. As of 2019, it is also the most rural, as only 13.25% of its people live in urban centres. There are 851 known languages in the country, of which 11 now have no known speakers. Most of the population of more than 8,000,000 people live in customary communities, which are as diverse as the languages. The country is one of the world's least explored, culturally and geographically.  It is known to have numerous groups of uncontacted peoples, and researchers believe there are many undiscovered species of plants and animals in the interior.