Here we are in the narthex. On the ground plan that would be 3.
The small vaults of the narthex are decorated with frescos depicting the Ecumenical Councils of the Christian Church (Ecumenical = before the Great Schism of 1054, when the Churches of Rome and Constantinople parted). In Eastern Orthodox tradition there were seven of them: Nicaea I (325 AD), Constantinople I (381), Ephesus (431), Chalcedon (451), Constantinople II (553), Constantinople III (680) and Nicaea II (787).
On the arches in between: frescos with the representation of saints.
The frescos must be dated around the 12th century, since this part of the church was built in the mid-11th century, and the city of Myra was completely deserted by the early 14th century.
Correspondent: J.M.Criel, Antwerpen.
Source: Website of ‘stnicholascenter.org’ & Wikipedia.