The park's wildlife includes several species adapted to high-altitude desert environments. Notable mammals include guanacos (Lama guanicoe), mountain viscachas, and small populations of pumas. The area is also home to various bird species, including Andean condors (Vultur gryphus), eagles, and several species of hummingbirds adapted to high altitudes. Reptiles such as lizards and small snakes are common, while insects and other invertebrates have adapted to the extreme conditions. The park serves as an important protected area for these high-altitude species.
Despite the harsh desert conditions, El Leoncito hosts a variety of adapted plant species typical of the high-altitude Andean ecosystem. The vegetation is predominantly composed of low-growing shrubs and grasses adapted to arid conditions, including various species of jarilla (Larrea), zampa (Atriplex), and coirón (Stipa). Small patches of high-altitude wetlands known as vegas support more diverse plant communities. The park also features important populations of Cardón cacti (Trichocereus) and other succulent species that have adapted to the extreme temperature variations and limited rainfall.
The park is situated in the Andean precordillera, featuring dramatic mountainous terrain shaped by tectonic activity and erosion. The landscape is dominated by the Cordón del Tontal and Sierra del Castillo mountain ranges, with elevations ranging from 2,000 to 3,000 meters. The geological formation consists primarily of sedimentary rocks from the Paleozoic era, including limestone and sandstone. The area's arid conditions have resulted in minimal soil development, exposing dramatic rock formations and creating a stark, desert-like landscape.
El Leoncito National Park was established in 2002 to protect the unique environmental conditions that make it perfect for astronomical observation. The area has been home to astronomical research since 1983 when the Carlos U. Cesco Astronomical Station was established. Prior to becoming a national park, it was a provincial reserve known as El Leoncito Astronomical Reserve. The park's name comes from the small lions (pumas) that historically inhabited the region. The area also has cultural significance, with evidence of indigenous Huarpe people who lived in the region before Spanish colonization.
The park's most distinctive feature is its exceptional astronomical viewing conditions, supported by two major observatories: the Carlos U. Cesco Astronomical Station and the Dr. Félix Aguilar Observatory. The remarkably clear skies, high altitude, and minimal light pollution make it one of the world's premier locations for astronomical observation. The park also offers hiking trails with spectacular mountain views, including the popular Cerro El Leoncito trail. Visitors can explore the dramatic landscape through marked paths, observe wildlife, and participate in guided astronomical viewing sessions at the observatories. The park's visitor center provides educational exhibits about the local ecosystem and astronomical research.
El Leoncito National Park experiences a high-altitude desert climate characterized by extreme temperature variations between day and night. The area receives very little rainfall, averaging less than 200mm annually, with most precipitation occurring during summer months. Due to its elevation (2,500m above sea level) and clear skies, temperatures can range from below freezing at night to over 25°C (77°F) during summer days. The region is famous for its exceptionally clear skies, with over 300 clear nights per year, making it ideal for astronomical observation. Strong winds, particularly the local Zonda wind, are common in the afternoon hours.
Argentina
-31.8000°, -69.2830°
2002
890
El Leoncito National Park is renowned for its clear skies and astronomical observatories. The park protects high-altitude desert ecosystems in the Andes Mountains. Its exceptional atmospheric conditions make it one of the best places in the world for astronomical observation.