Jeddah lies on the Red Sea coast in the Hijaz region of Saudi Arabia. It serves as a governorate, is the largest city in Mecca Province, and, after the capital, Riyadh, ranks as the country's second-largest city. Jeddah is the commercial center of the country. It is not known when Jeddah was founded, but Jeddah's prominence grew in 647 when the Caliph Uthman made it a travel hub serving Muslim travelers going to the holy city of Mecca for Islamic pilgrimage. Since those times, Jeddah has served as a gateway for millions of pilgrims who have arrived in Saudi Arabia.