Complex sentence: Broghol is a relatively low pass, only 3,798 meters or 12,460 feet high, and for that reason has been often proposed but seldom used as an invasion route.
Split into simpler sentences: Broghol is a relatively low pass, only 3,798 meters or 12,460 feet high. As a low pass, Broghol has been often proposed but seldom used as an invasion route.