Large natural arches are somewhat rare outside the southern and western regions of China and the Colorado Plateau of the southwest United States. Chad's Ennedi Plateau, located within the Sahara Desert in the northeast part of the country near Libya and Sudan has a geology similar to the Colorado Plateau and is home to a number of natural arches and similar landforms. Aloba Arch is considered to be the 8th longest known natural arch and has an approximate span of 75m. Perhaps more striking than the span, however, is the sheer height of the arch and at 120 m, it is one of the tallest known arches in the world. Seen here in the night sky, the Orion nebula places itself right in the center of the arch as it sinks into the western horizon….