World's Highest Mountains In Pakistan - The 1/4 area of the world is covered by mountains. The Gilgit Baltistan in Pakistan which is also known as the roof of the world is home of some world's highest mountain ranges—the main ranges are the Karakoram and the western Himalayas. There are many mountains which have not been climbed by anyone yet. The second world's longest range Siachen Glacier is situated here which is 75 kilometers long.