Going to the market... we joined them! The Hoang Lien Mountains are home to a rich variety of plants, birds, mammals, amphibians, reptiles and insects, many only found in northwestern Vietnam. For this reason, the Hoang Lien Nature Reserve was designated in 1986, covering much of the mountain range to the immediate south of Sa Pa. Forest type and quality change with increasing altitude. At 2000 meters the natural, undisturbed forest begins to be seen. Above 2500 meters dwarf conifers and rhododendrons predominate in the harsh “elfin forest”, so called because a lack of topsoil and nutrients means that fully mature trees grow to measure only a few meters in height. Higher still, only the hardiest of plant species are found. At over 3000 meters, Fan Si Pan’s summit can only support dwarf bamboo.