'Hills' in the Bible
The Midianites overwhelmed Israel. Because of Midian the Israelites made shelters for themselves in the hills, as well as caves and strongholds.
The leaders of Shechem rebelled against Abimelech by putting bandits in the hills, who robbed everyone who traveled by on the road. But Abimelech found out about it.
Gaal saw the men and said to Zebul, "Look, men are coming down from the tops of the hills." But Zebul said to him, "You are seeing the shadows on the hills -- it just looks like men."
She then said to her father, "Please grant me this one wish. For two months allow me to walk through the hills with my friends and mourn my virginity."
He said, "You may go." He permitted her to leave for two months. She went with her friends and mourned her virginity as she walked through the hills.