Árbol de Piedra, or the Stone Tree, is a unique rock formation in the Eduardo Avaroa Andean Fauna National Reserve in Bolivia's Potosí Department, near Uyuni. It's a popular stop on tours of the Salar de Uyuni and the surrounding desert landscape. Due to its remote location and natural terrain, accessibility can be challenging, especially for individuals with mobility issues. Visiting as part of a guided tour is highly recommended due to the lack of marked trails and the harsh desert environment. The best time to visit is during the dry season (May to October) for optimal weather conditions; the rainy season (December to February) can make some areas inaccessible. The cost is typically included within a larger tour package of the Salar de Uyuni, which can range from budget to luxury options, typically lasting 1-3 days depending on the itinerary. Remember to bring appropriate clothing for extreme temperature changes, sun protection, and water.