One of them is, of course, the world's biggest traveller Evilya Celebi (1611-1682), the other one is the symbol of the conquest of Istanbul, the Hagia Sophia, which this traveller described in his Seyahatname (the book of Travel) as "the Mecca of Christians". Both are full of mysteries; both have been researched a lot, written a lot and told a lot. And there is also that Evilya Celebi tells about Hagia Sophia in a more different way than anyone else has done...
To read Seyyah-i Alem's (The Traveller of the World) Seyahatname means to be friends with our great traveller prior to 400 years, to make a journey to that and previous period.
It is written a bit repetitive and because it is from an old book it is written in this style. Although it is a bit hard to read due to this still very interesting facts and beautiful images.