In the center of the excavated portion of the northern area was a mosque of the Abbasid period (late 8th – early 9th century). The mosque has a deep mihrab indicating the direction of qibla. The mihrab was plastered and has a square external face. The floor of the mosque was covered with reused burnt brick tiles. An external structure on the western side was probably the foundation for a staircase minaret, again an early Abbasid form. The northeast corner has not been excavated in the 1960s and revealed a set of fine bowls, small storage jars and basins of the same early Abbasid period. This mosque is the third and latest found at Khirbet al-Mafjar and completes the picture of a Muslim community in this palace and town.
In front of the mosque was a large yard and a deep vaulted cistern with a plastered pool, possibly for ablutions before prayer. East of the mosque was a paved walk leading to an entryway. The entry itself had two benches on either side and paving with fine Nabi Musa limestones. To the north of the entry was a small hammam, cooking area and many other rooms excavated by Awni Shawamra; this part of area 8 is not complete and must await further excavations