The Rainforests of the Atsinanana are a serial property comprising six components. They contain globally outstanding biodiversity and have an exceptional proportion of endemic plant and animal species. The level of endemism within the property is approximately 80 to 90 percent for all groups, and endemic families and genera are common. Criterion (ix): The Rainforests of the Atsinanana are relict forests, largely associated with steeper terrain along the eastern escarpment and mountains of Madagascar. Madagascar is among the top countries known for their "megadiversity" and features an extraordinarily high number (circa 12,000) of endemic plant species.