The Annapurna Conservation Area (ACA) contains some of the world's highest peaks (>8,000m), the world's deepest valley - the Kali Gandaki Valley, Nepal's largest protected area (7,629 km2), and Nepal's most popular trekking destination with over 50,000 annual visitors. Of all protected areas in Nepal, different areas within Annapurna receive both highest and lowest average rainfall (5,600 - 400mm).
Within the altitudinal range of 1,000 - 8,000m, ACA has an entire habitat gradient from sub tropical sal forest to perennial snow harboring 22 different forest types with 1,226 plant species including 55 endemics. About 101 species of mammals including many rare and endangered species like snow leopard, musk deer, Tibetan argali, and Tibetan wolf are found. Of 478 species of birds that are found in Annapurna, 38 breeding species belong to a group that are at risk in Nepal. The Kali Gandaki River is a major divide for bird distributions where species typical to both east and west Nepal occur. Also, Annapurna is the only protected area in Nepal where all 6 Himalayan pheasants of Nepal, are found.