Twelfth-century mausoleum of Momine Khatun, wife of the Atabeg Eldegüz Shams al-Din, designed by the architect Ajami ibn Abu Bakr al-Naxçıvani (one of the named masters of the Caucasian Islamic Middle Ages). 25-metre brick decagonal tower with intricate geometric Kufic inscriptions. The principal monument of pre-modern Nakhichevan; the surviving heritage anchor against which the destruction of the Julfa cemetery is commonly contrasted.