The renovated Aya Sofya basilica, a modest building, was the site of the Seventh Council of Nicaea in 787. The sanctuary visible today (which subsequently was converted into a mosque) was rebuilt by Sinan in the 16C only to fall quickly into ruin. The nave, flanked by two bays and enclosed by an apse, has preserved its synthronon (row of benches used to seat the clergy), along with an Ottoman mihrab. On the floor, a few attractive Byzantine mosaics are still visible - these date from the same period as the fine fresco on the north wall representing Jesus, Mary and John the Baptist.