Albert Barnes Commentary Jeremiah 25:12

"And it shall come to pass, when seventy years are accomplished, that I will punish the king of Babylon, and that nation, saith Jehovah, for their iniquity, and the land of the Chaldeans; and I will make it desolate for ever." — Jeremiah 25:12 (ASV)

Perpetual desolations - The ruins of Babylon form its only lasting memorial.