The Masjid-al-Haram is considered to be the holiest mosque in the world and the main destination of the Hajj pilgrimage. The Hajj pilgrimage is a trip that a Muslim is supposed to take as part of the Five Pillars of Islam, which are the five duties that are expected of Muslim individuals. During the Islam month of Dhu'l-Hijja, Muslims from all over the world travel to the Masjid-al-Haram for a pilgrimage that for many is an once-in-a-lifetime religious voyage. During these pilgrimages, men are said to enter a state of holiness when they are 10 kilometers from the site, where white sheets, called Ihram, are placed around their bodies. Women generally wear their own clothing, but cover their heads when making their pilgrimage. Muslims may make smaller pilgrimages, known as Umrah, to the mosque at different times of the year. Non-Muslims are not allowed to enter Mecca or its holy sites.
The Masjid-al-Haram was built in the 7th century, and has undergone a number of renovations and expansions. It has also been rebuilt several times. It was built during the reign of Caliph Omar Ibn al-Khattab, who allowed homes to be taken down in order for this structure to be built for the growing number of people making pilgrimages to Mecca. The mosque was built with a 1.5-meter-long wall, which serves as a place to pray outdoors. Under the reign of Caliph Uthman Ibn Affan, columns and arches were added to this prayer area. After Caliph Abdul Malik bin Marwan took control of Mecca, teak was put on the ceilings of the mosque and the capitals were painted gold. Other changes later included the addition of marble columns. Stone columns were then added to the outdoor worship area, the arches were painted with mosaics and later augmented with medallions, and minarets were put in the mosque for worship activities. The mosque now has an area of 356,800 square meters, and can hold up to 820,000 people at a time.
The Ka'aba is a building located in the courtyard of the Masjid-al-Haram. Its name means "a high place with respect and privilege." It is considered to be the holiest site in Islam because Muslims all over the world face toward it and pray five times a day, as part of the Five Pillars of Islam. This cubed building is over 49-feet tall with 1-meter-long stone walls and a room inside that measures 13 by 9 meters. According to the Qur'an, the building was constructed by the Prophet Adam and reconstructed by prophets Ibrahim (or Abraham) and Muhammad. Archeologists believe that it was built by ancient tribes as a shrine for holy objects and for the worship of tribal gods. After Prophet Muhammad's time, the building was destroyed and rebuilt several times, in a similar manner to the Masjid-al-Haram. The building that stands today only contains the original stones, and its ceiling and roof are entirely new. The shape of the building has also been changed, from its original rectangular shape to its present cubical shape. During the holy month, the Ka'aba is usually covered with a type of black silk with golden thread. One of the structures that sits within the Ka'aba is the black stone, which is an ancient stone that is believed to have been worshipped before Islamic times. The stone is part of Hajj, as Muslims kiss the stone when they are circling the Ka'aba as part of their Tawaaf rituals. As part of a reconstruction project during the Prophet Muhammad's time, the stone was placed into the eastern wall of the Ka'aba by clan elders.
