2 Peter 3:10-12

But the day of the Lord will come as a thief [i.e., unexpectedly]. At that time the heavens will pass away with a loud noise and the elements [Note: This refers either to the heavenly bodies or to the material components of the universe], will be dissolved with intense heat. And the earth and its works [i.e., its activities] will be burned up. [Note: Some translations render this phrase as it is in some ancient manuscripts, "will be disclosed," or "will be laid bare"].

Revelation 20:11

Then I saw a great, white throne and Him who was seated on it [i.e., probably Christ]. Earth and heaven fled from His presence and they were not found anywhere [again].

Treasury of Scripture Knowledge

Summary

And the mountains shall be molten under him, and the valleys shall be cleft, as wax before the fire, and as the waters that are poured down a steep place.

Bible References

The mountains

2 Peter 3:10
But the day of the Lord will come as a thief [i.e., unexpectedly]. At that time the heavens will pass away with a loud noise and the elements [Note: This refers either to the heavenly bodies or to the material components of the universe], will be dissolved with intense heat. And the earth and its works [i.e., its activities] will be burned up. [Note: Some translations render this phrase as it is in some ancient manuscripts, "will be disclosed," or "will be laid bare"].
Revelation 20:11
Then I saw a great, white throne and Him who was seated on it [i.e., probably Christ]. Earth and heaven fled from His presence and they were not found anywhere [again].