The term 'center of worship' can refer to two different places: an ALTAR and Mecca. An ALTAR is a raised platform or structure used as a place of sacrifice or worship in many religions. It is often found in churches, temples, and other places of worship. Mecca is a city in Saudi Arabia that is considered the holiest site in Islam. Muslims from all over the world travel to Mecca to perform the Hajj pilgrimage at least once in their lifetime. Both the ALTAR and Mecca are important centers of worship for many people around the world.