Vietnam has a diverse landscape ranging from jungles to forests to swamps. It was once heavily forested but warfare and deforestation have reduced forest coverage in some areas. However, Vietnam remains one of the most biodiverse places in the world, with over 10,000 plant species, some yet undiscovered. Several rare and endangered species call Vietnam home, including the elusive saola antelope and Cat Ba langur monkey which live in limestone forests. The largest turtle in Asia, the Cantor's giant softshell turtle, also inhabits Vietnam's wetlands and rivers, spending most of its time buried and only surfacing to breathe.