Mount Sun is one of the Five Great Holy Lands of the Ninth Mountain and Sea. 
According to the legends, Mount Sun was a fragment of lands shattered by the impact of the Immortal World’s sun when it fell from the heavens. Because it was so large, vast amounts of sun power could be found there, and as a result it was also the reason why there were so many powerfully destructive volcanoes there.
Mount Sun is a world of scorching heat. The land is like a desert, however there was no starry sky above. Mount Sun is its own unique world. The sky was dark, and the lands were parched. Countless mountains could be seen stretching out in all directions, all of which were spontaneously erupting volcanoes. The first time Meng Hao travelled here he noted that the a dozen or so of those volcanoes there were belching out black smoke, which shot out bright glowing arcs of light that looked almost like meteors.