Glass towers and mud-brick origins
Riyadh is Saudi Arabia's capital and largest city, a sprawling modern metropolis of highways and towers such as the Kingdom Centre, whose sky bridge gives wide views. Its history is best seen at Masmak Fortress, the clay fort in the old centre, and at Diriyah, the mud-brick birthplace of the first Saudi state, where the At-Turaif district is a UNESCO site. The National Museum is excellent, and out in the desert the escarpment at the Edge of the World drops sharply to the plain below.