A fortification or citidal in Jerusalem, built by King Solomon.

In the Bible, 1 Kings 9:24 reads:

"But Pharaoh's daughter came up out of the city of David unto her house which Solomon had built for her: then did he build Millo."

2 Chron 32:4-5 reads:

"And he strengthened himself, built up all the wall that was broken, raised it up to the towers, and built another wall outside; also he repaired the Millo in the City of David, and made weapons and shields in abundance."