2 Samuel 5:9

2 SAMUEL—NOTE ON 2 Samuel 5:9 The Millo (see 1 Kings 9:15; 1 Chronicles 11:8) was a series of terrace walls, built on a steep slope, that supported the fill dirt behind it to create level areas. Houses were built on these artificial platforms and connected by narrow staircases. During heavy rains, the fill became heavy and increased the pressure on the terrace walls. These required regular maintenance, lest the houses fall down the steep slope and the city disintegrate.