I love visiting historical buildings that carry the depth of culture. Usually such places are not promoted in the list of highlights in the city. You will need a couple of more days extra to visit these relatively off the beaten path sites. The first Ottoman Imperial Mosque, now called Fatih Mosque and Complex or the Mosque of the Conqueror, is one of such sites.
By 1470 Fatih had completed the great mosque which is comparable in size to the Haghia Sophia. This lovely structure has one huge dome in the center that rests on four elephant feet pillars which are also supported by semi domes. But the interesting thing is that this mosque was built on the ruins of the Church of the Holy apostles which was built during the reign of Constantinus I. As seen in most of the historical buildings in Turkey one holy spot is continued to be used as a holy spot no matter the religion. This is what makes İstanbul so unique.
If you have time, or can create time, visit this mosque. Don’t be shy enter and observe the interior. Perceive the light and the spiritual feeling and feel the peace and comfort.