Hagia Sophia Plan
In terms of the architectural sense Hagia Sophia plan combines the basilica plan with a centralized plan which is domed basilica type building. It is considered an important work in the history of architecture together with its dome transition and structural properties.
Before anything else Hagia Sophia is important with its size and architecture. No basilica structure is as great as a dome of Hagia Sophia in the world of that era and such a large interior space was not possible. Although the dome of the Hagia Sophia is smaller than the dome of the Pantheon in Rome, the half dome implemented in Hagia Sophia, complex and sophisticated system consisting of arch and vaults make the dome more impressive by providing the ability to cover a much wider space.
When it is compared with the previous dome structures fitted to the body walls as carries; such a large dome just placed on four pillars can be considered as a revolution in both aesthetic and technical sense. The main (central) dome covering half of the nave extended to create a great interior in a large rectangular shape with the half domes added to the eastern and western sides. So that you perceive these domes as a single dome that is hanging in the sky when you look at to the top of the structure from the central place.
Hagia Sophia floor plan is also another issue which should be discussed alone since it is also revolutionary when it is compared with its era. When you want to exit from the structure without going to upstairs, you will have to use the gate at the end of the southern part of the inner narthex. The mirror located on this gate is placed in order to remind the visitors that there is a mosaic left behind them. So that, visitors do not miss anything.
You can go to the second floor from a gate which is located at the end of the western part of the inner narthex through a ramp decorated in cobblestone style. This ramp used to provide greater convenience to carry the empress with her throne without being shaken when compared with the stairs.
It is possible to see some old brick arches on the walls of this ramp. The upper floor always devoted to women both in Byzantine era and Ottoman period. Today, it is still possible to visit this area in Hagia Sophia museum.