The Tree of Ténéré gets a special mention only because it no longer exists. The 10-foot acacia tree was estimated to be more than 300 years old and at the time of its demise in 1973 was the only tree for more than 250 miles. It was all that remained of a large forest that had been slowly swallowed up by the encroaching desert. It 1973, it was allegedly knocked down when a drunk truck driver hit it, the only thing standing in the middle of a wide open plain. Today a monument made of metal stands where it once grew.