The cupolas of the Kremlin
I've suggested leaving the crescent, provided it is impaled on the foot of a cross, the way you see it on top of the domes of churches St. Stephan of Moldova built to commemorate his victories over the Turks.From www.orthodoxed.org:
Sometimes the bottoms of the Crosses found on Russian churches will be adorned with a crescent. In 1486, Tsar Ivan IV (the Terrible) conquered the city of Kazan which had been under the rule of Moslem Tatars, and in remembrance of this, he decreed that from henceforth the Islamic crescent be placed at the bottom of the Crosses to signify the victory of the Cross (Christianity) over the Crescent (Islam).