'Hill country' in the Bible

And Abijah stood up upon mount Zemaraim, which is in the hill-country of Ephraim, and said, Hear me, O Jeroboam and all Israel.

And when Asa heard these words, and the prophecy of Oded the prophet, he took courage, and put away the abominations out of all the land of Judah and Benjamin, and out of the cities which he had taken from the hill-country of Ephra

And Jehoshaphat dwelt at Jerusalem. And he went out again among the people from Beersheba to the hill-country of Ephraim, and brought them back to LORD, the God of their fathers.

Moreover he built cities in the hill-country of Judah, and in the forests he built castles and towers.