Visiting Hail, Tabuk and Madina

Plz share if u knw any places worth visiting in Hail, Tabuk and Madina provinces? (except madina city)

Mad'ain Saleh is definetly a must go. Throw in Wahaba Crater to the trip as well!

Happy travelling!

Regards,
R

Mad'ain Saleh (Checked) - how much time is good enough to see Mad'ain Saleh?
Wahaba Crater is on the way b/w Riyadh and Taif thus it will not be on my way, but I have already visited it, planning to visit it in the winter so that I can hike down
Thanks