People describe China's landscape as being like a staircase with three steps. The top step of this staircase is in the west, where the Himalaya mountains are (India is on the other side of these mountains). Tibet is in this part of China. And Mount Everest is here (it's the world's tallest mountain). People call it "the roof of the world." The tops of the mountains have snow even in the summertime. In winter, the whole area is very cold - it can be as cold as -40 Fahrenheit (that's the same in Celsius). But in the summer it can get hot, up to about 100 degrees Fahrenheit (40 degrees Celsius). Panda bears live mostly in the mountains of south-western China.