'Upper' in the Bible

Then the Lord said to Isaiah, “Go out now to meet Ahaz, you and your son Shear-jashub, at the end of the conduit of the upper pool, on the highway to the fuller’s field,

And the king of Assyria sent Rabshakeh from Lachish to Jerusalem to King Hezekiah with a large army. And he stood by the conduit of the upper pool on the highway of the fuller’s field.