The Tree of Ténéré was a solitary acacia that was once considered the most isolated tree on Earth. It was a landmark on caravan routes through the Ténéré region of the Sahara Desert in northeast Niger, so well known that it and the Arbre Perdu to the north are the only trees to be shown on a map at a scale of 1:4,000,000. The tree is estimated to have existed for approximately 300 years until it was knocked down in 1973 by a drunk truck driver.