GOD Almighty created this earth so exquisitely. Earth is not only filled with flat ground, which can only be used to create a building for human habitation. But, there are mountains covered with trees as the abode of certain animals.
God created mountains as nails earth. Like a nail, an object made of wood attached to the wall will not last long if it is not nailed properly. Similarly earth. If the nail is damaged, it can be said of this earth will not last long. This is what will happen in the end times.
Rasulullah ﷺ already proclaim that one of the signs of Judgment is the disappearance of mountains of place. Either because disappear by itself due to the face of the earth, landslides and so forth. Or due to human activity as a result of the construction of up flattening the mountain like teradi present in a number of countries.
Samurah RA narrated that the Prophet ﷺ said, "Judgment Day will not happen until the mountains disappeared from its place, and then you see the great events you have never seen before," (HR. Thabrani).