'Upper' in the Bible

Then the Lord said to Isaiah, “Go out to meet Ahaz [king of Judah], you and your son Shear-jashub, at the end of the aqueduct of the Upper Pool, on the highway to the Fuller’s Field;

“Is not Calno [conquered] like Carchemish [on the Euphrates]?Is not Hamath [subdued] like Arpad [her neighbor]?Is not Samaria [in Israel] like Damascus [in Aram]?

Then it will happen on that day that the LordWill again acquire with His hand a second timeThe remnant of His people, who will remain,From Assyria, from [Lower] Egypt, from Pathros, from Cush (Ethiopia), from Elam [in Persia], from Shinar [Babylonia], from Hamath [in Aram],And from the coastlands bordering the [Mediterranean] Sea.

And the king of Assyria sent the Rabshakeh [his military commander] from Lachish [the Judean fortress commanding the road from Egypt] to King Hezekiah at Jerusalem with a large army. And he stood by the canal of the Upper Pool on the highway to the Fuller’s Field.