20 Every island fled away, and the mountains were not found.
Revelation 16:20 Cross References - WEB
Isaiah 2:14-17
14 for all the high mountains, for all the hills that are lifted up,
15 for every lofty tower, for every fortified wall,
16 for all the ships of Tarshish, and for all pleasant imagery.
17 The loftiness of man shall be bowed down, and the arrogance of men shall be brought low; and Yahweh alone shall be exalted in that day.
Jeremiah 4:23-25
Revelation 6:14
14 The sky was removed like a scroll when it is rolled up. Every mountain and island were moved out of their places.
Revelation 20:11
11 I saw a great white throne, and him who sat on it, from whose face the earth and the heaven fled away. There was found no place for them.