Jeddah, alternatively transliterated as Jedda, Jiddah or Jidda, is the largest city in Makkah Province, Saudi Arabia, and the country's second largest city after Riyadh, located along the Red Sea coast in the Hejaz region. 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.