 The church is situated in the middle of the fortress ' territory along the longitudinal axis . It belongs to the domed basilica type of churches , where the bearings join with the side @-@ chapels of the apse . Two pairs of arches divided the longitudinal stretched prayer hall into three naves , the central one of which ( with double side @-@ chapels ) on the eastern side ends with low staged , half @-@ rounded apse and the side @-@ chapels end with sacristies . They are characterized with stylish iconography , richness of theme and variety of different colors ( where blue is dominant ) . The vertical axis of the building was crowned by a massive dome . The pointed dome with the cylindrical drum has not survived . It was damaged during Tamerlane 's invasion and completely demolished in 1784 when the Avar Omar Khan invaded the Transcaucasus from Dagestan . In the 19th century , Viceroy of the Caucasus , Prince Mikhail Vorontsov built a semi @-@ spherical wooden dome covered with iron sheets in place of the original dome . The dome was renovated during Soviet years . 
