Around 621 BC, 2 Chronicles 35:
A few decades later, King Nebuchadnezzar of Babylon captured Jerusalem and raided the temple. There was no mention of the ark.
Fast-forward to Revelation 11:
That's the last time the Ark of the Covenant was mentioned in the Old Testament.1 Josiah kept a Passover to the LORD in Jerusalem. And they slaughtered the Passover lamb on the fourteenth day of the first month. 2He appointed the priests to their offices and encouraged them in the service of the house of the LORD. 3And he said to the Levites who taught all Israel and who were holy to the LORD, “Put the holy ark in the house that Solomon the son of David, king of Israel, built. You need not carry it on your shoulders. Now serve the LORD your God and his people Israel.
A few decades later, King Nebuchadnezzar of Babylon captured Jerusalem and raided the temple. There was no mention of the ark.
Fast-forward to Revelation 11:
Perhaps God took the ark before the Babylonians could get a hold of it and stored it for safekeeping in heaven.19 God’s temple in heaven was opened, and within his temple was seen the ark of his covenant. And there came flashes of lightning, rumblings, peals of thunder, an earthquake and a severe hailstorm.