Which valley did God promise to make a gateway (door) of hope in Hosea 2?

Answer: Achor

God promised to lead His people into the wilderness, speak tenderly, and make the Valley of Achor into a gateway of hope.

““Therefore, behold, I will allure her and lead her to the wilderness, and speak to her tenderly. There I will give back her vineyards and make the Valley of Achor into a gateway of hope. There she will respond as she did in the days of her youth, as in the day she came up out of Egypt.”— Hosea 2:14-15 (BSB)