Arch-In-The-Sky is a spectacular thin arch about 20 centimeters thickness located in In-Ahtim massif south of Idou site. This well-hidden arch has a span of 12 meters and a height of 3.2 meters height. The second opening below has 4.2 meters span. It is located at GPS coordinate 24 degree 50.526' 9 degree 29.381' . Note the author on the top of the arch for scale.