One of the most notable features of the site is the Green Dome over the center of the mosque, where the tomb of Muhammad is located. It is not exactly known when the green dome was constructed but manuscripts dating to the early 12th century describe the dome. It is known as the Dome of the Prophet or the Green Dome. Subsequent Islamic rulers greatly expanded and decorated it. Early Muslim leaders Abu Bakr and Umar are buried in an adjacent area in the mosque.
The site was originally Muhammad's house; he settled there after his Hijra (emigration) to Medina, later building a mosque on the grounds. He himself shared in the heavy work of construction. The original mosque was an open-air building. The basic plan of the building has been adopted in the building of other mosques throughout the world.
The mosque also served as a community center, a court, and a religious school. There was a raised platform for the people who taught the Qur'an. In 1909, it became the first place in the Arabian Peninsula to be provided with electrical lights.