The building consists of a central dome suspended over the Rock and octagonal walls enclosing two vestibules that surround the Rock. The vestibules are separated by an intermediate octagon composed of arches that are supported by corner pillars; between each pair of pillars were two columns. The Rock itself is also surrounded by arches, which are supported by three columns standing between each pair of pillars. Atop these arches is a tympanum with windows that held the dome. The building is accessed by means of four entranceways, facing the four cardinal points in the external octagon. (for a decsription by Al-Muqaddasi click here, for a description by Ibn al-Fakin click here)