Wadi al-Rummah or ar-Rummah is one of the Arabian Peninsula's longest river valleys, at a length of almost 600 km (370 mi). Now mostly dry and partly blocked by encroaching sand dunes, the wadi rises near Medina at Jibāl al Abyaḑ. It then runs northeast, joining several smaller wadis; among them are Mohalla Wadi and Murghala Wadi to the north and Jifn Wadi and Jarir Wadi to the south. It ends at the Thuayrat Dunes of the ad-Dahna Desert in Al-Qassim Province, near Buraidah.