Passage: Najd is a plateau ranging from 762 to 1,525 m (2,500 to 5,003 ft) in height and sloping downwards from west to east. The eastern sections (historically better known as Al-Yamama) are marked by oasis settlements with lots of farming and trading activities, while the rest has traditionally been sparsely occupied by nomadic Bedouins. The main topographical features include the twin mountains of Aja and Salma in the north near Ha'il, the high land of Jabal Shammar and the Tuwaiq mountain range running through its center from north to south. Also important are the various dry river-beds (wadis) such as Wadi Hanifa near Riyadh, Wadi Na'am in the south, Wadi Al-Rumah in the Al-Qassim Province in the north, and Wadi ad-Dawasir at the southernmost tip of Najd on the border with Najran. Most Najdi villages and settlements are located along these wadis, due to ability of these wadis to preserve precious rainwater in the arid desert climate, while others are located near oases. Historically, Najd itself has been divided into small provinces made up of constellations of small towns, villages and settlements, with each one usually centered on one "capital". These subdivisions are still recognized by Najdis today, as each province retains its own variation of the Najdi dialect and Najdi customs. The most prominent among these provinces are Al-'Aridh, which includes Riyadh and the historical Saudi capital of Diriyah; Al-Qassim, with its capital in Buraidah; Sudair, centered on Al Majma'ah; Al-Washm, centered on Shaqraa; and Jebel Shammar, with its capital, Ha'il. Under modern-day Saudi Arabia, however, Najd is divided into three administrative regions: Ha'il, Al-Qassim, and Riyadh, comprising a combined area of 554,000 km2 (214,000 sq mi).

Question: What is highest elevaton of Najd in feet?
5,003