Saudi Arabia is home to the holy cities of Makkah and Medina, but a pilgrimage route around the country doesn’t have to stop there. Travelers can venture to other holy — and less crowded — spots to enjoy the mosques’ calm atmosphere or pray in peace and to check out other sites of historical significance. Makkah and parts of Medina are accessible only to Muslims; however, other architecturally noteworthy mosques and historic sites acro...