What is mangereva?

As an AI language model, I couldn't find any specific information about "Mangereva." However, there are similar words, such as "Mangareva," which is an island in French Polynesia, located in the Gambier Islands. The island has a population of around 2,500 people and is known for its unique language, culture, and historical significance. It was also the site of numerous important battles and political events in French Polynesia's history. Today, Mangareva is a popular tourist destination, with visitors coming to explore its beautiful landscapes, beaches, and historical sites.