Historical documents show that several centuries ago Vitosha mountain was still covered by the remains of the inaccessible "Great Bulgarian Forest" (Magna Silva Bulgarica). Today, the natural coniferous forests of Vitosha remain only in the reserve Bistrishko Branishte and around Zlatnite Mostove (The Golden Bridges). The Golden Bridges is a stone river consisting of a ribbon of huge boulders running down the mountainside. This scenic spot is located along the Vladayska River in an area of mixed deciduous and evergreen forest. However, this is only one of the stone rivers found in Vitosha and they were once the moraines of ancient glaciers. Their further formation occurred due to the spherical erosion of the sienite rocks and their gradual movement to down stream valleys by the forces of gravity and moving water. At a time when nature conservation ideas were a long way from the present understanding, some enlightened noblemen took the first step in 1934 by declaring 66 km² of Vitosha a nature park, hence Vitosha became the first park of this kind in the Balkans. During the following year, some of the early Bulgarian reserves, Bistrishko Branishte (subsequently expanded to 10.61 km²) and Torfeno Branishte (7.84 km² respectively), were designated within its boundaries. The park boundaries fluctuated over many years and today it encompasses the entire mountain; an area of 266.06 km². It is the highest massif of Srednogorie mountain chain system, that includes also the mountains of Sredna gora range, Plana, Lyulin, Greben, Viskyar, etc. Ecology Due to a great variability in elevation, a rich diversity of climates, flora and fauna can be found within the park. Research has revealed that on the comparatively small area of the mountain there are 1,500 species of higher plants, 500 species of fungi, 500 species of algae, 326 species of mosses, and 200 species of lichens. Among the, 31 species are Balkan endemics and 52 species are included in the IUCN Red List of endangered species. The forests are mainly composed of Norway spruce and Bulgarian fir, with some Macedonian pine, Scots pine, and at the tree-line, mountain pine, and mixed deciduous forest at lower altitudes, mainly beech, birch, aspen and alder. Regarding herbaceous plants, well-established populations of Veratrum album are present on the mountain, as well as other species commonly called 'lilies'. There are also orchids, such as the East European green-winged orchid (Orchis morio) that grows in the higher