For decades it held the distinction of the remotest tree in on the Earth. Visible from a large distance in vast Saharan plain it used to act as a landmark in the desert for the traders/travellers travelling through the area.
Later at the very spot where the tree stood, some unknown artist created a metal tree from pipes, used tyres and empty drum, as a monument to the dead tree. Thus the location still acts as a landmark.
Image from Panoramio is by naglwitz
Image from Panoramio is by inivag
View in Google Earth Google Maps (In low resolution)
Info Source: Wikipedia
More details and photos at L'Arbre du Ténéré and
http://www.agadez-niger.com (in French). (English Translation)