The Bone Mountains - known to the Dothraki as the Krazaaj Zasqa or "Bone Mountains" - are the tallest, most extensive and largest mountain range on the continent of Essos and in the known world. They are located to the east of the Dothraki Sea and Red Waste, more than three thousand miles to the east of Westeros.
The mountains are formidably tall, dwarfing any of the peaks in Westeros, and run from the Shivering Sea in the north to the Jade Sea in the south. Maps show that the northern-most part of the region is known as the "Realm of Jhogwin". The foothills of the mountains on their north-eastern side are known as the Howling Hills.
There are three major passes through the Bone Mountains. The first is located east of Vaes Dothrak and links that city with the city of Kayakayanaya, at the eastern mouth of the pass. The road linking them is called the Steel Road. Further south, another pass carries the Stone Road from Lhazar to the city of Samyriana. Further south still, near the southern edge of the range, a pass carries the Sand Road from Qarth to Bayasabhad. A coastal road also skirts the southern edge of the range, linking Qarth to Yi Ti.
The Bone Mountains are a substantial new addition to the map of Essos. They first appeared in The Lands of Ice and Fire.