The Bone Mountains, commonly called the Bones, are a colossal Essosi mountain range. They stretch longitudinally across part of the continent of Essos, beginning at the southern coast east of Qarth. The Bones north of the Steel Road are known by the Dothraki as the Krazaaj Zasqa. The Dothraki sea and the red waste lie to the west of the Bone Mountains while the Great Sand Sea, the plains of the Jogos Nhai, and Yi Ti lie to the east. The Patrimony of Hyrkoon once flourished east of the mountain range.
The mountains are a natural land barrier between the western part of Essos known to the Westerosi and the exotic, mysterious eastern side of the continent.
Three routes go through the Bone Mountains. The Steel Road, the most northerly route, cuts between the Krazaaj Zasqa and the rest of the Bones to lead to Kayakayanaya, then skirts around the top of the Great Sand Sea and south to Trader Town. The Stone Road is the middle route from Vaes Jini to Samyriana. The Sand Road, the southerly route, begins at Qarth, heads far north, and cuts through the Bone Mountains from the red waste. The old Silk Road once reached Yinishar.